SSR, as hard as it is (and believe me I know) it's important that you don't talk with him anymore. I moved and changed my phone number. I'm not saying you have to be that drastic, but you might consider at least changing your phone number. When I had a tendency (and sometimes I still do) to minimize what he did, it helped to write out the cruel and hurtful things he said and did. While it was painful to do that, it helped me face reality. It's tempting to start minimizing the bad in order to hang on to the relationship, even when that relationship is toxic.

Another thing that helped me was telling a therapist what happened. It took some of the weight off my shoulders. I was so ambivalent about what to do, and telling the therapist took the decision of what to do out of my hands. I don't remember if you said you were in the U.S. or not but in most states in the U.S. (I'm not sure if it's all states) therapists have a legal duty to report this type of abuse. Telling a therapist was one more safety measure that I put in place to help me not communicate with him any longer.

It may be that he is contacting you now because he's getting nervous. Don't let him draw you back in to this.

I've asked the WHY question, so many times. I don't know that I've ever found an answer for that except to say that a therapist/psychiatrist who would do this has an overinflated ego and is basically screwed up in the head.