Is this a crush or am I in love with my best friend? 15f

I have a friend who is a nice shy quite girl she has been my friend for ages iv kinda liked her for 2 years but it was just a lol crush but now she is all I think bout I haven't been able to sleep people for bout a week now cause shez all I think bout she once told me she was bi but now she's straight what should I do I really like her I just want to go up to her and kiss her tell her how I feel but what if she says no it could distory our friendship should I tell her or not

If she's flipping back and forth between bi and straight that says she not sure who she is. What is the need for you telling her anything? Just be her friend and continue as it is now without losing her friendship. Once she figures it out, you'll still be there.