Whether or not you accept it, things are changing back home, too, and when you do make your first big trip back, things will not always be as you remember them. (I know full well that telling you that does no good, but you'll see - eventually.)
One thing to do is simply to start planning a visit back to "The Old Country." Not too soon, but in six months or a year. That gives you something concrete to work on - keep lists of things you want to stock up on, people to see, etc. It can be very different being back there as a "visitor" once you're settled in elsewhere. And, over time, you may find that you don't miss some thing as much as you thought. Keep track of how your lists change over time.
You might also want to look into things like Skype (for contacting friends and family - though the time difference can be a drag), online news from back home (TV channels often have news stories for online streaming) so you can keep up with what is happening.
Another thing is to keep a journal - both to record your experiences and to vent a bit when you start feeling particularly homesick. Sometimes writing it all out leads you to understand exactly what is "really" bothering you - and it isn't always where you are or what (or who) you're missing.
One thing to realize is that you will have mood swings, in about three month long cycles. Allow yourself to chalk things off to a "bad Germany day" - we all have them (well, I have bad France days, but the principle is the same). If there is any kind of expat or international club or group in your area, sign up for it. Sometimes you just need the company of other "furriners" so you can grouse a bit about local customs and habits that you don't understand. If you've got German friends, try asking them what American traits and customs drive them nuts (and don't contradict them when they tell you - just listen). You get a very different perspective on The Old Country when you let the locals tell you their stories.
Cheers,
Bev