I dont know what can i do....

Hi my name is Chris and i am 17. 1 year ago i met a girl it was a friends sister.We didnt have much contact but i was visiting her at her school and when she was seeing me she would just run to hug me and kiss me but as i saw she would do that with most of her friends.
Anyway for the last 6 Months i just couldnt get her off my mind because of that i sucked at school i couldnt study i couldnt even sit still.All day i am not kidding i was thinking of her so i asked for her phone and we started talking.3 days later i just sent her a messege to go out together but she told me that she had to study and she couldnt and that she wasnt in the mood->this isnt the bad thing
A frind of mine learned that i like her and started saying staff about her i almost kicked his ass and he was saying to me that before 22-30 january when her parents are missing he would stay there and sleep with her and then he started sayin she is a hore and staff
yesterday that friend of mine another friend and she got oute 2gether (i didnt know she would be there)she didnt even talk to me for 3 hours she didnt say a word!!!and all the times we met we where all day 2gether she was with him but noting happens between them.1week before we had gone to a club and she was all time with me anyway i dont know what to do because i heard that she likes a lot a guy (i dont know who) and i believe that if i made now my move nothing would have happened.Generally i dont have problems with girls when i need to tell i like them because most times i just like their body but this girl.......I really like it i dont know what the hell i can do but i just cant let her go like that i couldnt stand this!She is the only girl i have cried for withought even rejecting me.....

I Just thought that it would be possible to happen soemthing between us if the next time we met and we were alone i wouldnt just kissed her witought saying anything