I was invited to a church by a friend today and the one thing that stood out to me was the community; everybody was friendly and willing to talk to people they didn't know. The one aspect of atheism that I despise is the lack of people (especially my age) that meet up.
My friend is aware of my atheist beliefs and didn't invite me to convert me.
I am so happy for the internet as it has helped me find other Atheist sort of people. I belong to a number of Atheist/Freethinker and similar meetups. Though the number of our kind is small, they are out there. Another option might be a secular humanist group. There is one here that functions a bit like a church. They have Sunday programs for adults as well as for kids and have all sorts of activities, just nothing related to religion (other than educational).
Trust me when I say I know exactly how you feel. I have often joked with friends that I need to start going to church just to find a date. the greatest strength of all religions is there ability to build communities. Ultimately though this is not an endorsement of them just an admission of failing on our own Merritt's. As they say Be the Change you want to see in the world. We need to build this site and we need to build our communities not on atheism because atheism is not a belief structure or even way of living. We need to build communities on the idea of the great and beautiful creature that is humanity and all of the wonderful things we are going to accomplish in the future. We need to build a community around the idea of helping our fellow man and protecting each other and our interests through Unity.
I know we can all feel alone, but remember we're all here, here for each other.