Breakup and depression

I'll try to be as brief as I can. I was into a relationship with my bf for 8 years. He basically love bombed me throughout and was always so good, kind, caring, supportive, loyal almost too good to be true. And because of this I couldn't take account of his anger which was extreme. He would break anything in his grip or stab himself with it. Whenever our fights escalated he would self harm as in stabbing himself till he bled, banging his head on the wall, beating himself, strangling his own neck, all to scare me and when I cry to stop him he would make scary faces with red eyes. Even over phone call he would make noise like he's hitting himself. Suicide threats were an everyday thing. And no one other than me knows thisbat all, I fact people think he doesn't know anger at all. I never back bitched about him to anyone so nobody knew. He was almost obsessed over me and didn't like me spending time anywhere else. He didn't complete his studies and has a very low paying job. I brokeup with him when he threatened to kill me and my family. But then he was apologizing and begged me to stay which I didn't listen to at all. He even tried to commit suicide but survived and within months he married someone else. I feel like a fool because I still can't move on. I miss him terribly each day. I feel like I couldn't save our relationship, I fel like a failure.