Girls! Need advice about getting denied?

[Devan Green]

-Had 3 classes with this girl, I didn't notice her a first but after awhile I became extremely attracted to her.
-Talked a little, knew who each other was
-Friend tells her I think she's cute (without my knowledge, he's just that kind of kid that thinks it would be funny).
-She goes out of her way to smile at me at the gym and say hi.
-She waits for me to finish talking to my friends after class one day.

-I am really nervous, don't say anything, just smile at her, decide to message her on Facebook.
-Get a reply 3 days later, have a small conversation. Facebook chat isn't going well though
-work up courage to ask out on an ice skating date, wait a week, no reply yet
-two days left, message her to follow up, she says she's been busy so she can't go on the date
-"maybe another time" is what I say (but with some obvious disappointment)

I still like her but it causes me so much stress knowing it's for nothing, how do I get past this? Losing these feelings is tough.