Ugh sleep is overrated lol. I was up for nearly 4 days earlier this week before totally crashing down from my hypomanic state. The past few days have been awful.
Anyways, melatonin can play a HUGE role in helping you fall asleep, since it is the hormone that is naturally released when we are in a dark environment, and makes us sleepy easier. Getting exercise, and making sure that you go outside during the day can help a LOT. Trying to get out that excess energy, and being exposed to natural light are good ways to tire you out.
Good luck! If all else fails, I mean, being productive isn't a bad thing either haha.