Thanks everyone for your replies. I'm still really anxious about this, but at least I know I'm not alone in feeling like this - which does help. Until I found this forum, I thought I was the only one who thought like this.
I dropped J off at the airport this morning. He's flown to Atlanta, and will be taking off for Stuttgart in about 20 minutes. He called me from the airport about 20 minutes ago - which helped. He doesn't know about the GAD (since I didn't know about it until a few months ago), and I know I need to tell him, but I didn't want to drop all this on him right before he left. He knows that I always get really depressed and emotional whenever he has to go on these trips, but I don't think he has any idea how bad I really get.
Apple - I also worry that I won't be there if something happens. If I'm there with him - I don't feel as bad about these trips (although I really don't like to fly but that's another story). I can't sleep either whenever J is on a trip, especially out of the country. He'll be tired from being jet lagged, and I'll be tired from being unable to sleep and waking up constantly in the middle of the night. That said, you'll get through those three days in April just like I'll get through these 16 days - because I have to and you'll have to. There's no other choice, the trips will happen (no matter how much they suck). I've gotten better with shorter, more local trips, it's these long ones out of the country that are still really hard. Does having the kids around when your husband is out of town help any? We don't have kids (I can't imagine how worried I'd be), but they seem like they'd be a good distraction.

Basil - I know that you're right about using this time to work on myself and that I need to keep myself busy. Still it's easier said than done. I'll definitely be on the forum tonight and tomorrow, and probably a lot during the weekdays too since I work in IT so I'm always on the computer. I've checked out some of the other forums and found a lot of threads that I'll be posting on soon.
OE: I'm going to try and continue meditating, although I'm taking today off. I bought a book about meditating 8 minutes a day for 8 weeks to learn how to start meditating, and they say you're allowed to miss 2 days over the 8 weeks, so this'll be one of my days. I'll try to get back into it tomorrow. You're right about facing your anxieties, and I know that there's nothing I can do since he's on that plane and it's taking off soon, but still as you well know this is so hard to do.
Even though I know that the odds are significantly in my favor that he'll be okay - it's still really hard. He doesn't like international travel because of the long flights and the jetlag since he can't sleep on planes. Knowing that he'll probably be up all night (then get there at 8 AM exhausted) doesn't help either. I'll be up all night myself watching CNN to make sure there aren't any plane crashes. I used to bring the TV into the bedroom when I'd go to bed, but I've discovered it's easier to leave it in the office and just bring in a pillow and a blanket. Since there are now flight tracking websites I can track his flight all the way to Germany. The tracking used to give out around Iceland, but Delta now has some sort of transoceanic tracking. He's due to get in at 3 AM our time, and I have no doubt that I'll be up on the computer until then. Of course once he's there, then I start worrying about what'll happen since he's there ....
Besides all this I'll be trying to figure out some way that we can retire soon (we're in our 30's so it's not really going to happen anytime soon), since if we're retired - he wouldn't have to go on these trips and we'd be together all the time so I wouldn't worry as much. Or if only we could find some job/business that doesn't involve travel ....
I just checked Delta's web site and the flight's been delayed an hour. Last time he went to Germany his flight was delayed an hour and a half, and last time I went (to meet him there) mine was delayed 2 hours - so it figures. Just more time for him to be stressed on the plane and for me to be worrying ....