Me and my boyfriend broke up on saturday . I have to see him everyday at school. How can I get over him?

I am 15 and my ex is also 15 (we are both almost 16). We had been together for about 2 and a half years. We both lost our virginity to each other and he was my first love.Our relationship has been a bit on and off as he has a tendancy to make rash decisions when he is angry. a couple of weeks before we broke up this time he was talking about splitting up? I didnt quite understand this until he said to me that he got back with me the other times because he felt sorry for me. Obviously, i saw this as a bad Omen and a couple of weeks later i asked him whether he wanted to break up. After looking surprised he admitted that he infact did want to break up. I am crushed, i cry all the time and cant forget about him. the worst thing is seeing him at school and not being able to hug him and kiss him. seeing him talking with other girls makes me mad. i can be a severly jealous person? I need help but I just cant stop thinking about him. i used to spend alot of time with him , so now i am alone.