Shy guy that needs help.......?

She dam pretty, smart, popular, nicest personality, but she has bf, but they been together for long time!!! (im 15) i asked my friend to ask her what she thinks of me, she said im wired but very adorable, funny, nice and sweet and she asked my friend 3 times if i like her he said i could have feelings for her and she said that so sweet, but she said i have to talk to her first before she does anything. We stare at each other when p in the corridors, the look she gives me is out of this world, i tired to talk to her, but i cant her looks intimidates me, she the sweetest girl i ever seen. I think about all day, then 2months ago she broke up her bf, he was cheating on her,( cant believe he would do that to her, she had 4 year relationship with him) i have number on mxit, i was thinking to leave message about what think of her and my sympathy towards her, then come back later online and see how she respond, she walks past were me and my friends hang out, flirts with older guys, and stares at me constantly when she does this, what should i do, i love her and never seen anyone like her, just feel like holding her all day. Lately she hasn't looked at me, now when walks past me its like i dont exist, a month ago she looked at me whenever we ped, has she lost interest in me.