Dude, I know that hurts.
I'm probably a great deal older than you but when I was 52 years old (I'm 56 now), I came to realize that religion is a sham. My wife of 30 years divorced me, my daughters abandoned me, and I was forbidden from seeing my granddaughter. My son, who is also an atheist, has talked some sense into the rest of the family in the last few years so now I do get to see my granddaughter occasionally but it was a rough go for several years. They accepted my son despite him being an atheist but they totally abandoned me. Now, I am a bit more -- lets just stay "studious" -- and I'm better prepared than most to defend my position and make theirs out to be ludicrous, but he (my son) is a lot more easygoing.
Hang in there and be yourself. It's too exhausting trying to be someone else.