I understand how you feel and I also hide my true feelings a lot. My immediate family knows I’m a nonbeliever and usally don’t bring up religion around me but recently my 4 year old granddaughter ask me how come I didn’t believe in god even though I’ve never brought that up to her. I find that to be a little disturbing but didn’t confront anybody about it as it’s just not worth the fight.

I have no problem with it .if i like a person i do not care if they believe in a god i just go along with what ever they talk about but do not Encourage the conversation

I have certain tells: eye rolls, raised eyebrows, scoffing, etc. when religion is discussed. I don't even try to pretend. I don't feel comfortable misleading people about my beliefs. I don't feel compelled to reveal my disbelief to strangers, but I won't pretend to believe either.

Well first off I have no issue telling people about no god, if they ask, I do not attend and that is by choice, My friends are non believers and my acquaintances may be attend church but due to ideology, they will never become close friends. I see it as, if you even doubt god and attend or tolerate church, then you feel guilt.
I do not believe men hide this, perhaps you are meeting men from or near church and once again in comes the guilt.

I don't see a reason to hide my true feelings or personal convictions. The main reason western culture celebrates as many holidays as we do is that Christianity was so dour that it had to co-opt celebratory traditions from areas they wanted where they wanted to setup shop. Your motivation and tactic are very similar. Until your actions reflect your values, you'll most likely continue to experience a sense of being disingenuous.

My advice is stop pretending and just tell people you no longer believe....if in fact that is your position. You can’t live a lie, and you owe it to yourself to be honest. Going to church when you don’t believe in god is nonsensical and you will feel a lot better if you stop pretending. If your friends shun you after you tell them then they are not worth having as friends. Real friends allow you to be yourself and should respect your views even if they differ from theirs,

I have an adequate number and quality of friends without resorting to church. To the extent I would even consider "church" as a source of community it would be a post-Christian arrangement like Unitarian-Universalism, and then only an atheist-friendly congregation. Or maybe, in a pinch, a very liberal Christian denomination that is atheist-overlooking, typically in a "don't ask, don't tell" way. But in my experience such groups seem incapable of not forming cliquish groups around something -- if not dogma or doctrine, then politics or social class. So mostly I avoid them.

Part of your problem is living in rural or small-city midwest. I'm in a distinctly liberal / areligious enclave in the northeast where there's a large academic community and lots of NGOs and nonprofits to coalesce around. Of course ... thanks to family ties and financial / job constraints, it's non-trivial for most of us to just pick up and move someplace more comfortable. I had the luxury because both my wife and I are 100% telecommutes, and our nest was empty.

If you start saying "I don't believe in your Christian God" you will be surprised how many people agree with you.