How do i back off from my ex bf without him hating me?

im 16 now but my ex and i went out for 7 months and we got back together once after that, but since we broke up again its got even more complicated because he said we would get back together and so we got really close and started having sex again. But then he met another girl and randomly got with her so i went mad and we had a huge falling out.. they end up splitting up and she went back to her ex so my ex now hates her too. all our friends got together and had a party and i get on with him again we start forgiving each other but even though we know every single thing about each other and he misses me he doesnt want a relationship. his friends dont want him getting back with me becasue there all girls and i always try to make an effort with them but they just hate me :( now we just have sex and its really bad because i can't help it theres no one else and i guess i just turn to him :/ to make it worse he said the other day that he thinks the girl hes just broken up with is more attractive then me and i know she is but what am i supposed to do. everytime we stop doing anything sexual or relatinship wise he treats me just like a friend and i hate that. :( how do i move on because even though im just about to start college im on my study leave and theres just no boys about i just really need some one.