For me cardio (stationary bike) 30 mins a day, every other day, it's Magic. I'm a different person, mood-wise.

Strong second on this. It will feel like the last thing you want to do, but start lifting heavy stuff and be consistent. You will feel better, I promise.

It seems flippant in retrospect but I'm going through the very worst life experience imaginable right now and it's the only thing that helps me sleep.