Unfortunately nothing you are asking sounds unusual to me. Yes if you were severely concussed, brain damage is possible. Keep in mind that there is a huge spectrum of damage (minor to major) and that neurologists know very little about it really. My neurologist is German degreed and has also studied at Johns Hopkins and freely admits to how little they know. Physical exertion elevates my symptoms as well. Find a doctor who knows about PCS, not that many do. I had a concussion 24 months ago. I'm 57. I had several as a kid playing sports and recovered quickly (within 24 hours) each time. Not this time. I was out of work for 10 months, but have been back to work for a year. My headaches have never stopped and by that I mean 24/7/365 for two years. Still have occasional light and motion sensitivity and some inconsistent cognitive impairment. I'd say I'm 90-95% back to normal and I'm starting to think this is as good as it is going to be. But still, I'm much better off than I was during the first year and better still than the second year. Time is a great healer. Patience is difficult. Hang in there.