Bff or gf?

I think im falling in love with my bestfriend, who is a girl. Ive always considered myself straight but have recently done some experimenting with girls. My best friend, who is straight and has a boyfriend, is just so perfect in every way. She makes me so happy when im around her, her smile could change the world. I think im starting fall in love with her. And its not the friendly love, it feels like so much more than that, and I know she doesnt feel the same. What do I do?