It's a lonely, lonely life if you have no family and struggle with relationships. Not interested in assigning blame; sometimes people do the best they can but it's not very good.
It sounds like your mother loves you, but is a very damaged person. Have you reached some sort of acceptance of the way she was towards you?
At a guess your mum feels very guilty about the way she treated you - she knows it was bad- and can't handle even talking over what happened without feeling guilty.
In practise I think the best thing, if you can (and if it works for you) go to some skilled therapy. Nothing can undo the events of the past but you may be able to face some of the pain, accept it and move beyond it. That can be very healing. I think you need therapy on your own, but would she be willing to go to a different joint therapy? If she is the sort of person who genuinely tries then she may be very limited in how she can respond to you, but she may do her best. It will never be perfect with how damaged she is, but it may outweigh going no contact.
Beyond that some contact gives both of you something, but I think that you need to keep some distance (as you said you're doing). But it seems worth trying to have a limited, and careful, relationship. The point may come where you can't, where you need to step away, but it's worth working on how to handle her. Just keep some careful distance, and be aware she can never be the mother you needed when you were young.