I've been where you are.
in fact, I went from polyamorous and bisexual to monogamous and straight because I was married and in a religious cult. after the divorce, it took me years to fully leave the cult and embrace who I really am and feel ok about it. even before I accepted who I am, I managed to make friends with a poly bi woman who has become like my sister and just the exposure to her network of friends did wonders for me.
the other thing that's helped me most recently is joining a philosophy discussion group. I found that most of the people in the group are very accepting, and it turns out some are poly. if that kind of activity interests you, PM me and I can help you find out if there's one in your area.