Thanks everyone. I guess this has to do with trusting myself and my instincts/intuition better. I do tend to internalize and second-guess everything. On the one hand I would like to get better at being myself and contributing to conversations no matter who I'm with. On the other hand, most of these women ARE boring and I think there's a reason I didn't hang out with them much in school... I tend to over-think things and therefore assume it had to do with my drinking, but it was probably also because we just didn't have much in common and they weren't my kind of friends. It's so hard to know who I should be friends with and why because in the past my friendships tended to revolve around drinking.
Honestly the books they have been picking have been really stinking... I keep thinking of finding another book club anyway that is more in line with the kind of books I want to read. I know I could go more often and suggest my own books (I've started to try to do that and have been ignored but to their credit, I only come sporadically and don't contribute much so it only makes sense that their own suggestions are given bigger priority).
I think I will try to strengthen the friendship with the woman who invited me to the group and who is the one I may have some things in common with and like the best. But not worry too much about the other women, and only go to the book club when it's a book I really want to read, or otherwise just drop it.