I agree with the other posts... I've been with my boyfriend for almost 3 years one of which has been spent at opposite ends of the country at uni.. It is difficult but with skype and facebook he'll easily be able to contact you.
With overcoming the paranoia, just think that he's probably going to be thinking the exact same thing as you... you'll be in a completely new surrounding and whilst you may worry he'll find someone else he's more than likely to be thinking the same!
If you are 100% committed, then it can work, it all depends on your frame of mind, positive thinking is what will get you through it!