I'm lost.. :'(

I seriously liked my classfellow from when i was 8 and now I'm 16 and still cant forget him. He cheated on me , used me for his schoolwork , lied to me , verbally abused me and put me in lots of troubles in home and at school. I dont know why even after so much , i am not being able to hate him. Whenever i remember how he called me a slut , a bitch , I wish i could die. :'( This seriously pains in the hearrt :'( I have a bf. H eis very very caring and supports me although he is my ex bf and ex crushe's best friend. How should I get over my ex?