Here is a good lesson for the future. If you like a girl and want to be more hen just friends but she doesn't like you for anything other then friends then you best to stop being her friend altogether because by doing that, it gives you a chance to get over your crush so that other girls look attractive to you and you start to pursue them instead of just stagnating in your "friendship."
Ask her to be your girlfriend again at the end of homecoming and if she still says no then stop hanging with her so you can get over her.
I know you're going to balk at the idea of not having her in your life in some way but doing just that is the best way for you to get over her.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion