The hard part is getting started becuz, like you, my energy level is a bit off..ok way off...but
after the
workout, I eat better, feel like i have more energy and i think it may help with the sleep eventually. What really drives me though is the sweat...i believe, and may even be right (anyone?), that sweating will help get rid of any toxins you may have left in your body after opiates or anything else...just my thoughts...i'm no doc :-)
good luck...