I'm falling for this girl..but she's straight? :(?

[ღ тïkkïïღ]

So there's this girl in one of my classes it just so happens to be the one where we work in groups. She always sits next to me and we're partners for the class. I dont know why but I'm falling so hard for her. The way she looks at me she'll just look into my eyes and talk to me about any old thing . We worked on our project on friday and it was just us but it was great I felt like I could actually be myself around her. I even stuck an anonymous note in her locker saying she was beautiful. But then I saw that she was interested in men on facebook. I feel so stupid but I cant help but to want to try still. I cant get her off my mind. what do i do?