Ditto both hikermor and Chaos. When I was on active duty and stressing mentally, I found that stressing physically tended to balance it out -- endorphins or some such thing. Anyway not only do you get in better shape (which we all need) but the physiological toll of work related stress is countered.

So my advice is to work-out regularly and I mean to the point that you are physically wiped. You'll sleep better and if you watch your nutrition and fluid intake, you'll be better all around.

Then go look for another job. This one seems to not be a good fit personality-wise.