It is very difficult to get concussed without hitting your head or without being subjected to violent shaking that lasts a few minutes. You can get whiplash and whiplash can cause concussion like symptoms from upper neck injuries. Those whiplash injuries are not the same as a brain injury.

I suggest you get some ice grips to put over your shoes if you need to go out in icy conditions.

"dizziness, headache, ringing in ears doubly loud & a bit of nausea." can all be from anxiety.