I didn't know it could be so hard for people in America - where do you live?? I live in California so I have never experienced a problem even though I live in a conservative county - they are all pretty much secular.
One thing though; look at this one brightside through all the difficulties: if you were living in an Islamic country you might have been executed.
In my case, my immediate family is pretty liberal, so I've had no problems with them. My extended family is heavily evangelical, but extremely nice people who would never do or say something hurtful... at least not to my face. I have found out about some things said behind my back that were less nice, but I don't know who said what or what the details of the situation were, so it's hard for me to say whether there is much of a problem there or not. The feeling I get is that the blame for my atheism is being put against my parents, who apparently have put up with a lot of crap.
The most direct confrontation comes from coworkers who are almost all Christians. Nearly every time I've mentioned that I'm an atheist, some coworker instantly starts quizzing me on evolution or the big bang, like I'm supposed to be some kind of scientist. Though honestly the more intense conversations at work always revolve around politics. When I say that I'm a moderate with liberal leanings, they hear "communist."
My friends and family already know that I don't go to church and that I'm not religious, but I bet they have no idea that I am an atheist. My parents dropped by (without calling first) on their way home from church on Sunday and the first thing my mother did was pick up was a book I had laying on the table called "Raising Freethinkers - Parenting Beyond Belief." I don't think she looked at it long enough to really get the gist of what it was or if she did, she probably wouldn't want to believe that I am an atheist. You're brave for coming out and you will make new friends with common interests.
My full sympathy to you ): Inevitably, when you come out as an atheist you will probably lose one person close to you-but looks at it this way, if they would not tolerate your atheism they are probably people you would not want to be close to.