What do I do??????????

Im in a bad way about a girl. I am madly in love with her and i would do anything for her, she is the most beautiful, funniest, prittiest, awesome girl i have ever met, she is all i think about, i have lost lots of sleep just thinking about her, and am doing not to well in my subjects because of this matter. We spoke, i found out we have similar interests and we seemed to 'click' sorta, anyway so it was ok, just as two ppl who occasionally spoke, but then a rumour spread that i liked her, i dont know if she heard but i bet she did, it went awkward, we stopped speaking. Then after a while i attempted to approach her, it went 50/50 really and i thought it failed, but after a bit she approached me and i paniced and f****d up and she now thinks im a complete idiot and doesnt even seem to notice my existance any more, i tried approaching her and she was nice, left and never even looked at me afterwards, i am madly in love but i know i blew it. Help? She leaves very soon.