Losing my boyfriend...

To the army D:
He's been wanting to join the army for a few years now, as long as I've known him, and we've been together for over a year now. Now he's gone through with half of his interviews, he just needs to go have his physical and whatnot. The main thing he wants to do involves being right in the middle of all the action...
Honestly, this is killing me inside. I'm trying to look happy and excited for him but all I can think of is the long days without seeing or feeling him, the terror of not knowing whether he'll come home or not, the reality that we are probably going to drift further apart and end up breaking up. We've come so far together in the last few years and relied on each other so much, the thought of a life without him is a terrifying thought. The pain of losing him would be too much to bear.
So I'm gonna cherish the time we have together now, when everything is so simple.
Have any of you had this kind of problem?