Cut ties with family

I am the adult survivor of severe sexual, physical and emotional abuse in childhood. The perpetrators were my whole family, including a brother, parents and maternal grandparents. I have been living overseas for over 8 years now and have cut off all contact with my mother, who is the only family member who has not yet died or simply disappeared. I couldn't handle talking to her on the phone any more and listening to her manipulation, immaturity and verbal abuse. The only way I could confront her with all this stuff was by letter as I seem to regress to the level of a 7-year-old when I talk to her. She eventually responded with a card but basically doesn't want to address any of it. I don't really want to either as I can only seem to survive on the other side of the world, well away from her negative influence. This isn't about punishing her it's about me being able to survive. I am in therapy which is going well and also taking Zoloft which helps a lot.

Did I do the right thing in cutting off contact with my mother? Do other people do the same thing and do they regret it later on? I so badly need someone to tell me I am not bad for doing this and that this was OK to do since it was for the sake of my survival. Of course, my own therapist will not "judge" what I did but I really need someone to tell me it was understandable and healthy.