Please help me! I LOVE HIM to death! But he doesnt feel the same :(?

i met the sweetest kindest guy ever last year, hes ayear older than me, now im in grade 10. At first we became the closest friends, and he would I.M me everyday, but one day he met this girl (same age as me), then over the march break last year they got really close and the girl even told me that she liked him..i never told her my feelings though (were not exactly close friends) Theyre both in my nightschool chemistry cl this year. I think she took that cl just cuz he did..anyways at first he would talk to me mostly in tht cl, but then he started talking to her more and more and now he only says hi to me and asks me for help in chem when he needs it. we're still good friends and we both kno tht will nvr change, but he doesnt know i luv him..the girl told me tht they were going out, i never belived it at first and i told myself it wasnt tru, but then when i asked him he said it was true. i went home and i cried almost everyday i cant stop thinking about him i luv him sooo much!