I experience the same things.

Here is a few things that are worth a shot that have worked for me to have more uplifting days.

I made myself a morning routine of when I wake up I get onto my computer and watch a few videos that have me in them from random events before the injury. I also look at pictures from these events also. It sort of reminds me the way things were before. It may just be false hope but it seems to work well for me to at least make a terrible moment a bit better.

Also I write things down I did throughout the day that brought me to feeling better even if just momentarily.

I hope this helps