MAJOR CRUSH ON BEST FRIEND!! help

So I'm 14 and I'm bisexual. My best friend is gay and she is the best friend I could ever ask for. We're so close. the problem is I like her more than a best friend. I have day dreams of her telling me that she likes me and stuff like that. I don't know if I should tell her how I feel or make a move or do nothing? I don't wanna ruin our friendship.
Advice please?