Why won't he just leave me alone?

I am beyond frustrated. I have been in love with a very horrible man for the past two and a half years. We have been off and on. He has done a lot of very cruel things to me and I have allowed it. I have always been the one to walk away, and he has never let me stay gone. I have always said that he is my Kryptonite. Last week was my breaking point. I cannot deal with him, and deal with my medical issues. I have been battling my fibromyalgia. I took myself off Lyrica in May because not only did it make me put on 80 pounds, it made me loopy and I was losing my memory,couldn't remember anything and I am KNOWN for remembering everything! I was diagnosed with endometriosis about 11 years ago, and had a thermal ablation five years ago, but off and on this past year I have been having severe pelvic pain. So I was put on two new meds to treat endometriosis, an antidepressant used to treat pain and an antihistamine?? But it's giving me relief!
So I decided I was totally and finally done with this man. And I said so last week. Then this morning he texted me that he loves me. And I just ignored him. My best friend sent him some vicious messages which make me love her all the more!! I just cannot understand why he will not let me stay gone when I leave. I have been his security blanket so to speak since we met. He has told me things that he has never told anyone else. And the sex was unbelievable. Which is what he always says he can't let go of. Sex is sex. I want him to be honest with himself that I am more to him than great sex. But I don't think he ever will. Which saddens me and frustrates me. I just want him to let me go. He is just a little boy that ain't never gonna grow up. And I do not have the time or patience to deal with him and his little games anymore. I told him I was done and I did not want to ever see him or talk to him again. I cannot do it anymore. DONE.