I am not working right now, but I can relate to falling asleep during the day. Like when I am working on a project for school, my eyes would literally close at the computer. Have you talked to your pdoc? For me, this ridiculous amount of Seroquel I am on is causing it. Maybe it's your meds??

And as far as falling asleep at your desk, do they allow you to have books or coloring books at your post? Are you a guard or something? Maybe if your mind was engaged you wouldn't fall asleep? I hope you figure it out soon.

Hugs.