I can relate. I managed to get myself terminated on account of my absence. I had no motivation or energy to keep working long, physically demanding days and nights. And it is even more difficult when you have anxiety. My anxiety keeps me up til morning most nights which has also resulted in missed interviews. I have tried jogging lately for the simple reason of "feel good" endorphins that are released during the exercise. I try working out often in hopes of tiring myself out so by the time night falls I might get a decent sleep. It doesn't work though, neither do all the sleeping pills. Have you tried other places of employment that are no so demanding?