acmartin,
I have a very similar situation to yours so know that you are not alone. I have had around 6 minor concussions over the last 2 years that have now led me to have the same problem you are having with sensitivity...walking, car rides, etc. This has been very frustrating as I'm sure it has for you. I have a few questions to see if we share similar symptoms:

Does your forehead often feel hot? When you had your concussions in the past, did your vision go completely white for a brief moment? And how long have you been so sensitive to car rides and walking and have you gotten any less sensitive?

So sorry to hear about your situation. Hang in there