I'm familiar with this (not personally, not on that level). It sounds like the worst part is that deciding which way it's going is pretty much a judgement call. And an overwhelming one at that.

I have no real relationship advice to offer. I have avoidant personality disorder (which is a completely different kind of train wreck). However, I did have some relatives that caused me terrible anguish in my youth. It took me a long time to make that call. I do sympathize with the struggle.