Turn your fear into curiosity. Read a lot about science, especially evolution.

There is not one thing to be afraid of. I predict that your courage will grow day by day and that soon you will be very comfortably exploring various religious or non-religious options with impunity.

Just enjoy your new freedom.

It's going to take a minute.
However, I promise you, you were never going to be "punished" by "god" for anything.
There is no god to fear, and there is no hell to fear.

Most of us (non-believers) do the right thing simply because it's the RIGHT thing, not because we fear hell if we don't. Statistically, we're actually less likely to commit violent crimes. Further, the majority of prison inmates identify as "christians".
It's an extremely rare occasion when you hear about anyone identifying as a
non-believer committing violent crimes. I'm not saying we're perfect (no one is), but
we're generally an awful lot more law-abiding than believers tend to be.

Think about it. Think about the level of hypocrisy in those who ONLY do what is right because they fear their god. It makes everything they do less than genuine.
They're only being "good" because they believe they'll go to hell if they don't.
They also believe that if they do anything wrong, all they have to do is ask 'god'
for "forgiveness" and then they're all good again. So, they can act badly with
impunity, because all they have to do is ask for forgiveness. How fucked up is that?

You do not need to be "terrified" of anything.
You are being your authentic self, and you don't need delusions to be a good person.
You know you're doing the right thing.

Know NO fear.

It's hard for me to relate to this because I never believed in hell. Look, heaven and hell don't exist. Versions of them go back to the stone ages when humans couldn't explain things. It's not coincidence that heaven is depicted in white clouds, and hell as some kind of fire cave. Because if you look up you see clouds. If you look into the earth you see fire, and that's because that is what's there. That's what ancient humans knew and imagined, and they passed it down for thousands of generations. What we actually come from is cosmic, stellar, and earthly nature, and it took billions of years for it to happen. I cherish my fellow man because I know how special we are in that regard. How truly amazing the human race is. But it isn't easy. The only thing you truly have to fear is living, so live it right. Peace.

You may find Humanism comforting. Defined as: "a philosophy or life stance that embraces human reason, ethics, and philosophical naturalism while specifically rejecting religious dogma, supernaturalism, pseudoscience, and superstition as the basis of morality and decision making." This could be your way to transition from believing in the Almighty Unknown to finding yourself researching and discovering more about the actual world: the natural world and human society/culture.

Watch Cults and Extreme Beliefs on Hulu. You'll see how these various groups manipulated their members. It is easier to recognize when it is not personal.
You'll see the parallels in all of them and perhaps to things in your own life.
It may clear more of the misty fog from your emotions.

Leaving religion is not the same as a disbelief in god. Perhaps you just can't abide religion but still have some faith in the western notion of creator being who punishes his creations. Just a thought.

Fear is the main part of religious control and why many laugh when confronted with evidence as they don't want their hopes (afterlife) destroyed. Not killing another person is empathy and logic in that it's not right. A religious person could easily use a scapegoat to do wrong by thinking God told them to do it. Have you actually read the Bible; it's full of horror and bad deeds mostly by God. Good for you bro by choosing to fight that cancer of the mind. Dr. Seuss books have way more morals.

I feel exactly the opposite - when I was under the illusion of my christian indoctrination and ever since I saw the move "The Exorcist" I was plagued with nightmares of demons and evil spirits trying to possess me and I had to constantly rebuke their attacks in the lords name - Ha! ...especially alone at night? Once I moved away from that crippling delusion - I felt completely liberated and my fears and nightmares vanished ...hallelujah!

My immediate reaction (usually the truest) is that fear is a product of religion. That's what they use to indoctrinate you, keep you in and to recruit more people into it. When you discover enough about life and reality to have the courage to face it on a daily basis on your own, then you'll be okay without religion. You have the desire to do that, you simply need to pursue it daily, pat yourself on the back for it. You'll continue to develop a better sense of self living in a real world and will feel more secure with that and without religion. It's that simple. Notice I didn't say hell once, except for right there, because it's not real.

Without the fearmongering and continuous sentimental reinforcement, this feeling will wear out at some time.
People will still try to win you back by fear, but remember, no adult is a good boy because he wants gifts from Santa Klaus

It takes awhile to get over it ... the situation will ride itself out. I felt the same way when I was young. I am now in my 60s and the fear has gone away. You will deal with it just fine. Trust me, you will.

There are a couple of ways you can shake the fear, although you would need to elaborate on what exactly you are afraid of. Many people go through a phase where they still think there will be divine retribution for them. I believe this is what you are experiencing so I will start with that. To get over that fear ( or any for that matter ) you are going to have to confront it. In this case that means finding something that you were told is wrong but aren't morally opposed to, and then doing that thing until you feel comfortable with it. ( don't break the law, thats not what I'm saying )

You may be worried about what your friends and family will say if they don't already know, and that can be quite challenging. There are tons of ways you can handle this, ( they all suck ) I would try to do it in the slowest most controlled way possible. If they care about you, then they won't judge you for being who you are. Everyone should be who they want to be, do what they want to do, say what they want to say, and not worry about what other people say to them.

Other people ( myself included ) go through a phase of nihilism, where you realize that there is no ultimate purpose or goal, and in fact the question doesn't make any sense. Some people return to religion if the feeling of existential dread is to much to handle, the rest realize that it never mattered if there was or wasn't a reason for our existence and enjoy the remainder of their lives.

The final type of fear is the kind from hate, usually from extremists groups who are intolerant ( usually and hypocritically because of their religion ) of non believers and other religions. If you have reached this stage, I can give you very little advice having never had to deal with it. There are however individuals on this site more qualified to discuss that subject.

I think you need a healthy dose of Alan Watts . Here's a taste, if it's to your liking check Alan Watts on YouTube . I think he would lead you in the right direction.

If you are intelligent and reasonable you cannot be the product of a mechanical and meaningless universe.

Figs do not grow on thistles, grapes do not grow on thorns, and therefore you, as an expression of the universe, as an aperture through which the universe is observing itself, cannot be a mere fluke.

Because, if this world peoples as an apple tree apples, then the universe itself, the energy underlying everything, what it's all about, the ground of being itself, must be intelligent.

Now when you come to that conclusion you must be very careful because you may make an unwarranted jump.

Namely the jump to the conclusion that that intelligence, that marvelous designing power which produces all this, is the biblical God.

Be careful.

Because that god, contrary to his own commandments, is fashioned in the graven image of a paternal authoritarian beneficent tyrant of the ancient near East.

It's very easy to fall into that trap. Because it's all prepared, institutionalized in the Roman Catholic Church, in the synagogue, in the protestant churches, all, they're ready for you to accept.

And by the pressure of social consensus and so on it is very natural to assume that when somebody uses the word god it is that father figure.

-Alan Watts

For all your life you have been indoctrinated about that there is a God. A lot of people in your community will not like your stance and try to make you see "reason" but that is their reason. There is fear that how am I now going to be perceived in my family or my community and maybe you will wonder for some time what if I am wrong. Well it does not matter if you are wrong as long as you are a good person. A person who cares about others and this earth we live on. If there truly is a god than that god would be ok with it. There is no need for you to "scream it from the rooftops" just go about your day as you always did but without the going to church or worshiping. It is nobody else business but your own. One day at a time is what it takes. You will find others who feel like you do, and you always have us.

Letting go of the guilt of "sin" is hard. But when you realize that the only guilt you need feel is when you are rude, inconsiderate, or harmful to yourself or others, it gets a lot easier. Especially when you remember that there is no Hell or any sort of punishment or judegement after death. Just live the best life you can with empathy, compassion, consideration of the feelings of others and respect for everyone. Be honest in all your dealings and feelings. It's really not that hard. And it gets easier the longer you do it. Also, if you're doing the best you can, don't worry about what other people think. Just do your best. That's all anyone could ask of anyone else or themselves.

EDIT: I assume you already conduct yourself this way. I was more getting at your need to accept that that is good enough.

Keep remembering that nobody knows what happens after we die. Most of us here feel certain that when we are gone, we are gone. We do not come back.

It takes awhile to shake that childlike fear of "hell" ... it took me well into adult life. I looked at science and found no proof that we exist when our bodies quit ... if our "souls" keep on living, we don't know where they go. Maybe we go back to the stars. We are all made of stardust.

I was never terrified of leaving religion, but I was never that "into it" anyway. I do feel guilty for things that have nothing to do with me-- such as having the nagging feeling I should have been able to help with things that happened before I was born. Is that weird? In any case, I recognize it as irrational and set it aside. That's what I would say to do with the fear of hell, and any other fear you have leaving religion.

I was very blessed as a child, my parents kept their beliefs largely to themselves in the religious sense, not that they were non believers though! I grew up in an environment of free thinking with choices of my choosing and have never adhered to or been indoctrinated into any direction spiritually. This, dear reader, was a very "critical thinking" place to have evolved and has put me at an advantage over those who's minds were closed at such a tender age. The process of cleansing oneself of learning by rote the thoughts and beliefs of others is painfully clear in your entreaty for the support of your peers and fellow free thinkers. I wish you strength in your seeking freedom and hope you find that we who believe in ourselves, in truth, in justice and the innate goodness of our fellow man, need no other master.

I experienced a lot of that when I finally decided to face reality. It would sometimes almost come to the point of panic attack when I thought that I was doing wrong or evil (premarital sex, drug & alcohol use, blasphemy...the guilt list goes on and on would set it off). I got through it by reminding myself that these feelings come from years of indoctrination and no actual moral failing. I stuck with my head and ignored my heart for a few years and it eventually dissipated and now head and heart are aligned. You are undoing indoctrination and it feels scary sometimes. Be bold and forge on.

There is no heaven, there is no hell, it's all made up. We only have this moment, make the most of it.

It may sound crazy, but go outside somewhere quiet, look up and say "You don't exist!"
Unless you hear a clap of thunder and a voice saying "Bollocks!", that should help you overcome your irrational fears.

Just keep in mind that the only reason people fear hell is because they have been brainwashed into believing in it... A while back the Pope Francis admitted that hell is an invention of the Vatican that dates from the Dark Ages and the Vatican shit itself denying it... Keep in mind that Christianity derives from Judaism which can be traced to 723 BCE after the conquest of Palestine by the Assyrians who sent them into exile where they started the new religion... They demonized Egypt because of the matriarchal culture there that would have allowed their women to divorce the stone age goat rapists they were married to... As for doing harm to others if you need a god to prevent you from doing that what you really need is a good shrink instead so you can get the mental help you require.

[vox.com]