You can find SAD lamps made for this. I think there are even some that attach to your body. "Verilux HappyLight" is the best I could quickly find, not recommending it exactly, just as a starting point.
But I agree with the person who said "movement". I get that's kinda a "solve your problem by solving your problem" piece of advice, but it's just kinda how it is. It just sucks a little but forcing your way through will make it better, and eventually you grind the habits in

