Why does my ex boyfreind hate me or acts like it ??

Me and my ex dated for three and half months i loved him he seemed to love me and it seemed a perfect highschool relationship then the christmas holidays came he went on holidays with his family for five of the six weeks he finally called me three days before school was due back he seemed okay he seemed to love me the night before school started we were texting each other we flirted then we had a fight about me hating myself and why i loved him .. i don't know why it just happened the next day i was angry for some reason at him i avoided him all day that night i got a text from him saying that he was breaking up with me .. after that i was hurt then it turned into hate and now fear , at school he acts like i don't exist and when he does notice me he gives me a stony look and his freinds are horrible to me he also insults my freind who is a guy .. help why is this happening to me i want to reconcile with him .