the biggest mood factor would be the sleep it doesnt matter how much you think your body has become accustomed to low levels of sleep any elevated sleeping patterns generally show positive mood improvements. I could start throwing studies at you if you like (big one by kwong-lee and michaels I studied in PE just to name one) Big tunes are great because they get the heart pumping, release endorphins and shit just gets hectic. If you dont have any sleep, your endorphins and other feel goods are going to stay locked away. If your generally djing when you are tired and overworked, then you brain is going to associated the negative body feeling with djing. Nek minit, even when you've had some good sleep and you go to dj you still feel terrible. its a vicious cycle. Im applying the same logic here as I use for elite swimmers (trust me when you start making big squads you do a million and 1 psychology courses), because ion reality your training yourself. To hit that next beat, vocal etc. My advice would be to try and get alittle bit more sleep. if that means you have to suffer alittle bit in other areas then so be it, but thats a small price to pay when compared to loosing the lthings to love. Get more sleep and I guarentee everything will gain a new more vibrant shade.