One thing I've learned about rejection is it is easily the most overestimated, self-inflicted pain a person can go through. Not to diminish your anguish, but to gird your loins:

The tricky thing about rejection is you're requiring a value judgement of yourself from someone whose opinion you are already overvaluing. You are basically asking the person you're most attracted to whether or not they judge you worthy of their reciprocal affection. If you look at it this way it's a horrible prospect and, if you have little self-esteem, the bad outweighs the good.

But look at it another way - you are paying someone a huge compliment. The only way that's bad is if you're creepy and uninvolved with them. If they're someone you're friendly with, the only way to lose is if you make it awkward.

This is the crux of confidence - recognizing that you're good enough, and close enough friends with - another person to think they'll be flattered by your advances, rather than embarrassed. And here's the secret: others follow your lead. Nobody knows "you" quite as well as you do and if "you" think that "you" are a creepy shitheel that no one would ever date, everyone else is likely to agree. If, on the other hand, "you" think that you're a fairly interesting person with a couple cool dance moves and a bunch of interesting hobbies that knows how to show a girl a good time, the girls will mostly take your word for it until they've evaluated you on their own.

If you think you're worthy of her, you are. Even if you don't think you're worthy of her, FAKE IT. You may find that with enough practice, you can fill even your own oversized shoes.