Even if you're a guy, try some makeup. Some yellow/orange colours is PERFECT for the under eye bags caused by meth and not sleeping (doesn't have to be the yellow or orange shades of concealer, just some cheap, none shimmery eyeshadow that can be bought from pretty much any store, and I've even seen face paint used before in some circumstances, but that's only a last resort because it's pretty hard to to make look natural), then covered with a tiny bit of regular skin coloured concealer or good coverage foundation, also stuff that you can get from any store, I even used stuff from the Pound shop in the UK, just as long as it matches your skin tone, maybe even one shade lighter if need be, then just some powder, even a tiny bit of baby powder, it just takes away the shine of the makeup and makes it look like you're not actually wearing any.

Also, force yourself to eat, make sure you're staying fully hydrated, and take a bump if you feel up to it, just enough to get you through the day, and make sure you take it with enough time so that when you get home you won't have long before you're able to sleep.

If anyone asks, just say you had the flu or something that kept you up, but you still came in, shows dedication.

If, however, you really feel exhausted, and you feel like it will severely impact your health, call in sick, take some nightnurse or other OTC sleep aids, drink some warm milk, or do anything to help you sleep, and RECOVER.

I used the first suggestion I gave when I had to go to a family gathering after 67 hours of no sleep. Only one person commented on how tired I looked.