If your room is 50 degrees you might as well just pack it up.
It might have dropped below freezing, causing the cells to rupture and lose their turgidity.
Growing in the attic is a pain in the ass... believe me, I have plenty of experience in attic growing, lol, you will spend most of your energy just on climate control.
Bare minimum you're going to need is a heater and an a/c on timers to even out the temps, and it's going to take tweaking to get it right based on your weather THAT DAY.