I'm on the last 2 weeks of a co-op assignment in 
Florida (I'm from Michigan), and I'm going 
through similar feelings, although a "check 
engine" light coming on 2 weeks before I have to 
do a 26 hour drive kind of adds to things as 
well. (as best as I can tell, it's nothing to 
really worry about though)

I'd also found that some of my problem is that 
I've just been sitting around inside too much 
(well, it HAS been raining a lot) and not getting 
out to get in some excercise as often as I 
probably should.  Not sure if it'd work for you, 
but it might be worth it to try getting out for a 
short jog / walk / bike to get your heartrate up 
a little.