Honestly, and I don't mean to make you feel bad but this just screams of not working out. I would honestly prepare myself and would seriously consider your lives at w/e age you are at and would just move on. It seems you both are in different stages of your lives right now.
It's painful to lose someone you truly care about but you can always remain friends. It really depends on how mature the both of you are and how realistic you think your relationship truly has of "making" it in this extreme situation and distance.
From my experience w/ my friends and myself, it never does work out in the end. Usually its just broken off or someone finds some other person to take up that time while the other person isn't there. Im not saying she would cheat on you or you her, but lets not kid ourselves, we are humans, and it's typical to do those things. We seek to fill the void so to speak, and 5 years and months apart regularly, is very difficult on both parties.
Hate to be a harbinger about it but it's a very difficult situation and the emotion of being apart truly isn't worth it as far as I am concerned.
Sorry to hear about your situation. It sucks.