How long are you two going to be apart?
If it's temporary (year or less), try to think of it as a test. You CAN get through it- just keep talking to each other and telling each other everything that happened during the day.
If not, it's still a test...but more of an extreme challenge. In this case, expect lots of fighting, but know that you can get through it. For the sleeping thing, get body pillows. They snuggle to you kind of like a body does.
I've been in a long distance relationship for about two years now. We see each other every other weekend, only because nwlinkvxd drives four hours home. It's been tough but now I'm finally moving in with him the beginning of June.