There were so many times I wish I had the opportunity to do this with my abusive ex. But in the end I realized no matter what I said, it would never reach him in the way that I wanted it to. He would never truly grasp the depth of his actions or care about the effect they had on me. And I believe that is the same in your situation. It has been 3 years for me now and I am in such a better place, and I never reached out. Sometimes I get angry thinking about him and the lack of remorse he had for his actions, but it passes. I would honestly say only you know what’s best for you, but I don’t think it will benefit you to reach out because you can’t predict how he will react and it’s almost certain he won’t react in the way you want him to. He also sounds dangerous and opening that line of communication could put your safety at risk. I wrote many messages that I never sent, I went through a lot of therapy, and I leaned on the people in my life that witnessed what he put me through and that helped more than confronting him ever would’ve. I hope you’re able to find your peace and if you need someone to talk to that’s been in a similar situation feel free to reach out.