This girl is really confusing me...?

...and makin me feel weird about myself. She likes me, this much I know. BUT she doesn't want a relationship... My best friend's girlfriend and this girl I'm speaking of are best friends, and I have been told that tthis girl likes me, but she doesn't act like it. We'll be textin and she'll just stop replying to my texts. It makes me feel like sh!t cuz I don't know what the eff is goin on.

What should I do? I don't get to see her that often, and when i do she's very shy and it makes it hard for me to talk to her, even though she talked to my best friend and was like "yeah i like him, we have a lot in common"... I don't know, i think that i just suck at getting girls. this is the first girl that i've ever gotten this far with (pathetic for an 18 year old, right?) and i don't want to lose her cuz i like her and she likes me but she doesnt want a BF cuz she's been hurt so much in the past by her ex's.

I just need some legit advice on what to do. she is driving me NUTS and I don't know what the heck to do with this girl...