My best friend and I used to "hate women" because pretty much all the bimbos we went to school with were the catty, back-stabbing ones you speak of.
But I refused to let that control me, and eventually developed a really good sense of which kinds of women were good to be around. Not all women are like you describe, though if you've been hiding out and avoiding them, then it's easy to see how you would feel that way.
The other part of this is, it sounds like you believe "being poly" means that you have to be in a threesome-relationship, where you're supposed to be girlfriends with the other woman. This usually doesn't work out even for bisexual women who love other women, never mind straight ones. So if this is what your husband is pressuring you to do, just tell him straight up that you're not interested.
Gralson: my husband (works out of town).
Auto: my girlfriend (lives with her husband Zoffee).
The most dangerous phrase in the English language is "we've always done it this way."