I cant get over my ex-boyfriend?

He was my hero and helped me through so much. He swore he loved me and that we'd be together forever and we got engaged and we bought my wedding dress and his family and my family were so excited making plans. But we fought almost everyday, he still talked to all his ex-girlfriend and some didnt even know who i was. I told him i didnt feel comfortable with him doing it and he said he didnt care. I've never felt so insecure about myself until i met him. He made me feel like **** but i couldnt stop loving him. i ended up getting pregnant and he swore it wasnt his and then wanted me to get an abortion even though when we were intimate i said i wanted him to wear a condom cause i didnt want to get pregnant and he was like no i want to get you pregnant and when the time came i wanted to keep it and he said no and made threats. a month after we broke up he had replaced me with one of his so called "friends" that he talked to that i said i wasnt comfortable with. its been 4 month since the break up, I've been promiscuous and angry. I cant go one day without thinking of him. when i meet a guy i'm thinking of him and get angry and i dont care what i'm doing. when i get home almost everything in my room reminds me of him when i go on myspace or facebook there he is with his new gf. i listen to old voicemails of him crying telling me he loves me and we will be together forever that he promised that everything will fall into place. and then i cry myself to sleep. i wish i could erase everything i knew about him, I'm tired of walking around and going to work with a fake smile so people dont ask whats wrong. we still talk, i'm trying to at least be his friend. I dont know why someone who caused me so much pain is someone i feel i cant live happy without.