Thanks all for your thoughtful replies.

@MtnWkr - I can relate to missing someone to hang out with, but not missing the individuals. I spoke to my therapist and that really helped. She always helps me see that I'm not as bad as I think I am.

With some people, including the female friend in this situation, I become completely naive when it comes to their views and opinions. I assume that whatever they say or think must be right - I think it comes from previous gaslighting experiences in therapy where I was convinced that my reactions were wrong, or the result of some failing on my part. It is/was hard to see that some behaviours aren't cool and my reactions are valid.

I think part of the last straw was that I ended up being her caretaker in a few instances, when I was not ok emotionally to take care of myself, let alone someone else. She confided in me about how other people had "betrayed" her (basically by doing anything not in agreement with her), which was a great guilt trip to make me stick around. I can feel anger coming up just writing about it. The advice I got from another mentor, and my therapist, was to avoid contact but not formally lay down no contact boundaries yet. And that our mutual friends don't necessarily think I've done something wrong.