I am in a relationship and i still love my ex!?

i have been with this boy for around two months now he claims he loves me and would do anything me but i still think about my ex everyday i thought i had finally got over him but it has been 10 months since we broke up and we were only together for about 3 weeks that time but i was with him four over times before that and words cant describe how much i loved him even though i am only young i know i do a day actually hasnt gone by were i haven't thought of him and the worst thing is i havent spoke to him since then i understand we will have both changed loads but i was at a party the other night and he kept looking at me and it is even harder the fact i have to see him walk around school everyday and still be friends with all my friends but i cant get over him at all i hate it i wish i could get over him but i cant i want him so much so i dont want to forget him but i cant break up with my boyfriend i told him i loved him and i told him i wouldn't know what to do if we ever broke up and i know he isnt going to break up with me anytime soon but i cry my self to sleep everynight it wouldnt be as bad if i wasnt with this over boy i like a lot also he is in like all my lessons at school and i sit next to jim in most of them please help me get over him?:(x