Well, but, don't we all make complete asses out of ourselves all the time? The question before anything is, do you and this girl get along well?
Alrighty. Well, it sure is pretty sucky when you're really into someone and nothing ends up coming out of the situation. BUT, how do you know at this point in time this is to be the case with you? I can actually relate to the way you're feeling, I'm in a situation where I can't quite be with someone I'm in love with, too. But then I try to stay positive. I really think it all depends on how you look at things. If you have already became friends with this girl, then you don't have to worry about her disliking you. If she didn't like you, she wouldn't have become friends with you in the first place. There's a chance of her not liking you in the romantic way, but then this essentially applies to every potentially romantic encounter and thus worrying about it is pretty much a waste of time. Take your time, get to know her better, and do NOT fear making a complete ass of yourself in front of her. Use that to your advantage even! Girls like a good sense of humour in guys. If you make an ass of yourself, make it into a joke and make her laugh. Hang out with her more often if you can...well, without getting too stalker-ish though, obviously! lol If she values friendships a lot, then she'll probably be inclined to remain a friend to you even if she doesn't like you in the romantic way. I've had female friends like that, and I'm glad I'm still friends with them. So even if that were the case, you still wouldn't be losing something special even though it might seem like it at the time. And if she actually DID like you back, then you could just be like WOOHOO!!!! Keep it real dude!