I know what you mean about getting fatigued but not sleepy, being exhausted but unable to sleep is very frustrating at four in the morning. Another thing I find is that I don't yawn like I used to which is strange. I've read that concussion can affect the bodies circadian rhythm, I know I seem to get a second wind at bedtime.

I'm going to try going back on 5htp to see if that helps now the sunlight is getting less. I used to take it an hour before bed and I think I slept more consistantly. Magnesium is another sleep aid which is said to calm the brain.

I think if you can achieve sleep consistancy then that's a good thing as you can build on it. Ironically the more you recover the more alert you become, which is where I am, and more difficult to switch off! I see this as a phase.