Smoking ban aside, those late hours, loud music, constant standing, and stuffy ventilation all add up. The "Beauty SOS" thread is good for tips that help you look better:
http://www.thefashionspot.com/forums/f45/beauty-s-o-s-morning-after-73249.html (Please don't take offense, as I am not assuming that you stumble home drunk after every night of DJing, but the effects of staying out late are similar to a hangover.)
Goes without saying that makeup will only mask the problem, and what you really need is to relieve stress and get a decent amount of sleep. Only you know what you can do to ease your stress, but I strongly suggest that you allocate your next "free" day or night for some serious rest. Scientifically speaking, no matter how sleep-deprived you are, get one long, deep, and undisrupted session of sleep, and you're as good as new. God, it sounds like I'm writing about sex
As for your skin, you could take a look at the various anti-fatigue products that are out there. Guerlain Midnight Secret, Clarins Flash Balm, and SKII Facial Treatment Mask all have a cult following amongst hard-partying nightowls; I've never tried them, so I don't know if they live up to the hype. My one "miracle" product is Korres Wild Rose face mask - it helps me look glowy and rested when I'm exhausted.
Best wishes on getting some much-needed rest and relaxation