What do I do?! I have a crush on a girl, can I have your insight?

I’m 16, a girl in highschool. Okay, there’s this girl. I met her last year, and she’s great. From the minute I saw her, I couldn’t keep my eyes off of her, there was just something about her. I have her as a friend on a social networking site, and she comments almost all of my pictures complimenting me in the most flattering ways,

I’ve seen the way she’s acted around girls before, and I figured she might be bisexual. I’m too scared to ask her but it’s beginning to take a toll on me, all I can think about is her and how I want to get to know her better . I’ve dated boys, plenty, and I’m very attracted to them, but I’ve never had feelings like this for a girl, could it just be physical attraction or am I bisexual? Please, I need insight, guidance, something. I’m losing my mind!