I don't want to make an assumption about your life. Everything I say is for you to test against your feelings. But here's what it seems to me. Your conscious orientation is that you've cut off friends before for fear they would hurt you or that you were bad for them. But that sounds like a defense mechanism rather than the original wound underneath it. In your dream it is the other people who are abandoning you. So I think the original trauma was being abandoned.

This doesn't have to mean a literal abandonment. Infants can feel abandoned when the mother is not emotionally available. Infant states are super intense, and your dream seems a lot like states I'm familiar with myself from my own life, and my own belief that my mother was emotionally unavailable in my infancy.

Also, the abandonment wound doesn't mean your caretakers were all bad. People have this way of compartmentalizing their experience, so all the good experiences go into one area of the psyche, and all the bad experiences go into another area. It seems that your dreams are coming out of the place in your psyche that feels nothing but abandonment. Hence it feels like utterly total abandonment, even this very harsh judgment that you are not simply bad but actively harmful to other people, even though your history may not contain a literally total abandonment event.

But I just realized you said you've been in therapy. What does your T think about your life history and the origin of the current nightmares?