I need help with this girl really bad?

Ok, its kinda complicated so ill try to keep it. She liked me for over a year, but up until recently I never did. Finally, I asked to a dance and a couple of dates. Apparently, she wanted me to ask her to b my girlfriend, but the one actual chance I had I got scared and didn't. This was 3 weeks ago. I've tried to go out with her 5 times, but each time she says she's busy. Now, all her and my best friend do is flirt. I keep trying to ask her out and talk to her, but im ignored. really like her, but right now my best friend is being a pain in the ***. He knows I like her, but he does it anyway and shes starting to fall for him. My friend has already tried to steal 2 other guys girlfriends. I don't want to lose her if I haven't already, but I don't know if i should talk to her, my friend, or just wait and see how things go.I need help with this girl really bad?
it seems like you've tried to get her back and shes not interested.so im guessing the only thing you can do is wait and see how things go.hopefully your friend mess up and you could comfort her and win her back.I need help with this girl really bad?
Well sorry mate, you missed your chance. That happened to me and i ignored the guys advances on me. It hurts sometimes and maybe now she has moved on and likes your best friend. You can't stop both of them going out and if they like each other you have step out the way, but let her know how you feel! At least then i think it will be better.

Good luck and don't fret, you'll like lots of girls..