I think Sixpack has it pretty well spot on. I'm sure it's just that anticipation that's getting you. It's like that last hour of work that seems to just drag on forever because all you're doing is looking at the clock the whole time.
I'd also tell you that while you've mentioned keeping your depression under control, I don't know that this necessairaly means that you're depressed again. I've been depressed, I've been anxious. This Saturday was the 1st year anniversary of the day I lost my dad. I don't consider myself to be anxious or depressed right now, but I sure cried like a baby when I thought about that day and the doctor coming into the room to tell us the heart surgery was unsuccessful. Not to get off point, but I guess what I'm trying to say is that me being sad about my father and you missing being home aren't bad things, they're not mental health issues per se. It's just one of those things that happens sometimes. As you said, you just can't wait to get back. Don't beat yourself up over it. You'll get there soon enough! In the mean time, sixpack is right that finding some things to do to help pass the time will help you greatly. Just try not to worry that something is wrong with you. You want to see your friends and family. I'm sure they apprecaite knowing that they mean that much to you!