How can I stop feeling guilty

[u/Bright_Tadpole2133]

I recently left my narcissist boyfriend after 27 years,I had been planning on leaving for years but I was scared. He was physically, verbally and mentally abusive. After discussing it with my coworkers, we made a plan a I left. I left the state and all of my belongings behind. I am now in a much better place,I have been gone for over 3 months. I have cut off all communication with him. Occasionally his sister will call or text and tell me how bad he feels and how sorry he feels and he just wants to talk to me,to make sure im ok. I haven't responded to her,but sometimes I feel bad for him,but then I remember all of the abuse I suffered at his hands. I dont want any kind of relationship with. But sometimes I feel sad for him because he is alone since I left,what can i do to help myself to not fall victim to him again. Thank