i recommend talking to a doctor, and making sure you don't drive while sleep deprived. keeping a log of any kind of it may help, but again, i'm not a doctor! :P anyway, bust of luck to you, and for me at least, the "getting away" with something because i was "good" got to be old, and i realized i wasn't getting away with anything or something, i dunno... i guess my point is I felt that way too, and my perspective on it has changed some. best of luck!!!!!
I can definitely relate to the boss saying "your schedule is getting insane." That's where the guilt starts to come in, and boy, all I can say is it's a good thing I'm good at my job and it's worth it to the company to let my schedule fall where I'm most productive. (EDIT: By which I mean, I feel unbelievably grateful and lucky to have such a flexible job.)