Hello! My name is Dr. Aida and I am glad to attend you on Healthcaremagic! Your symptoms are quite common after a head concussion. Anyway, I would recommend you to closely monitor your blood pressure values. Low blood pressure could be the cause of fainting. I would recommend performing a Head Up Tilt test to investigate for possible orthostatic hypotension, which can lead to this clinical situation. I would also recommend checking thyroid hormone levels to exclude a possible thyroid gland dysfunction. Hope you will find this answer helpful! I remain at you disposal for any further questions! Kind regards!