I’m having a hard time accepting an abusive ex

For context I was in an six year abusive relationship. To be honest, it wasn’t truly abuse until after the first year. He showed signs of serious mental problems after the first 8 months but he didn’t start abusing me until after a year. During our time together he would scream at me for hours on end at the top of his lungs, he tried to jump out of my car multiple times, he would yell at me if I didn’t have sex with him or do the sexual acts he wanted me to, he would make me participate in violent CNC, dress up like a child during sex which I didn’t want, he has left me at gas stations hours away from my house, he sped down the street threatening to kill me and everyone in the car, he blocked me from entering my home/leaving his multiple times, he slapped me, tried to smash my phone, and harassed me digitally by spamming my phone with 100s of messages and calls. If I’m being honest I used to post about him on Reddit constantly. Asking if the things he did were abuse, rape, and if I should leave. I think I wanted someone on here to tell me to leave and validate how I felt because he made me feel like I deserved everything. In February on Valentine’s Day I left him for good. I left because he had played music loud until 3am when he knew I had to be up at 6am. I had mentioned to him to turn it down or off, and he went crazy. He threw my book bag, threatened to kill me, and threw all my stuff off of the bathroom counter that he said “took up too much space”. I left his house at 3 am and he chased me in his car. The next day he showed up to my house unannounced to drive me to class. I got in his car stupidly and he immediately started screaming when I didn’t apologize. He left me on the side of the road after speeding down the street, hitting himself and me, and again,spam called me. After this he would show up at my house to scream at me, to threaten to kill me, and throw things at me. I finally decided to block him and stop talking to him. I had reached out to a couple of friends of mine who were still friends with his sister and had happened to work with him. I let them know I would be cutting contact since he had severely mentally, physically, and sexually abused me. Of course I didn’t expect them to tell him but they did. Each time they did it put me in harms way but I kept ignoring him. He called me and begged for me back until literally last month. Well, he has a new girlfriend. He is really good to her from what it seems and it seems like their relationship is healthy for now. I had reached out to her and let her know what he was texting me/calling me. She called me a psycho… I understand why I wouldn’t want to believe it either. I then sent her a text explaining I had nothing to gain from texting her and it actually puts me in danger with him reaching out to her but I care about her because I was with him for so long and I know what his manipulation is like. She called me a compulsive liar and I didn’t answer further. Anyway, I think about her a lot. It hurts and triggers me still what I went through with him but I worry for her. If he got away with it with me, I worry what he will do to her. I feel bad for her nativity and the fact that she thinks he will be good forever. But I hope he is, I think it’s just hard to know what’s coming. Especially since he was cheating on her, sleeping with me, and begging for me back before I knew they were together. They had been dating for more than three months before I knew that he was cheating on her with me and I feel bad. I feel horrible for her because she is very sweet and I feel… easy to manipulate due to her naive nature. I was like that when I started dating him at 16 and he was 19. It’s just hard and I don’t know how to feel.