OK, here goes. You'll probably all think I'm a little weird, but that's OK.
We all seem to work through so much when we dream. Dreams can seem to be a magnification of conscious or subconscious thoughts.
Dreaming about dying after a head injury seems quite natural to me. You were maybe scared you were going to die or never be the same again even if it was just a fleeting thought or you could have been worrying about the repercussions of a 2nd concussion.
From time to time I have lucid dreams and they're not concussion related although I have had a concussion. I once dreamed a very vivid dream where I became stuck on a ledge very high off the ground and there was no way to go except to fall and end it. I was trapped. However, I made a conscious decision to fly in my dream and saved myself. I can still remember it.
Maybe one day ProAgonist you won't feel paralyzed in your dream and you'll get up. The fact that you recognized in your sleep that it was a dream shows that you can lucid dream. All you need to do is change that feeling of being paralyzed into something more positive.
To me dreaming about death or dying is about change.
Dreaming about killing yourself? Well I think that could be very different.