I think night time is hard because it signals the end of the day, the conclusion remaining in inconclusion. The problem - whatever it is - still isn't solved. Instead, I'm still depressed, despite my strangely recurring hope that it will be gone. This depression remains, and will most likely still be with me in the morning. I get to look forward to another day with depression, and that is depressing.
Well, maybe that's it. I keep trying to figure it out. Meanwhile, I'd better eat and go to sleep, since sleep can make tomorrow a little better.