I suffered from similar insomnia for little over a year during my PCS recovery. I would often go for days without being able to fall asleep. My anxiety about it would get so bad that I would often devolve into violent rages between 3 and 4am. I tried many supplements, systems, techniques and ideas during this dark time.

I now sleep like a baby. In fact I think i'm sleeping better now than even before my concussion problems. I attribute the large majority of this success to a specific program for cognitive behavioural therapy for insomnia (iCBT). It's a 5-week protocol where you interact through email with the doctor that created the program. It cost me $50. This program saved my life.

http://www.cbtforinsomnia.com/

Good luck

Hains