At your age? Move on. I am in a much longer distance relationship than you, but we are both taking the steps to get together. We are much older though and know what we want. You are just 20? You need to date many more women anyway to figure out what you want in a relationship. (trust me, you don't know this yet) Get in the game and tell this woman if fate brings you two back to the same part of the country and you are single then you'll consider it means you should give it a go with her. Otherwise, move on. She is likely considering it also. Make the move before you get dumped yourself.
LOL, I didn't read this before I posted. Pretty much says what I said but in a harsher (but funnier) way !
You should move on with your life man. Like you said, your young and at this point you shouldn't feel like you should change your life for someone who isn't willing to change her plans to include you. Even so you should probably find a way to break up face to face, even if its off of skype.