Yeah, I find it impossible to take what I need and leave the rest at the meetings. But you've been doing that for a bit now, and it seemed you were being successful at it.
I never advise anyone against at least trying AA, atheist or otherwise.
That crap that happened tonight isn't really about AA. It's schoolyard crap and personality crap, and picky crap.
Speak with your buddies and think on it. I would advise trying to go back, at least once.
I kept trying and went to different meetings for a while, it just didn't pan out for me.