Minimac,

Since it has been 7 years since your only concussion, I highly doubt that you have any sensitivity to bumping your shoulder and the related jerking of the head. If your only symptoms is anxiety, then, your anxiety is the only issue. When I have a minor bump, sometimes I experience no symptoms at all.

Other times, I experience a visual disturbance, a metallic taste in my mouth, and a struggle focusing my thoughts for a few minutes. It is these symptoms that signify a concussion.

If there are no symptoms other than anxiety related symptoms, it is NOT a concussion. But, I doubt any of us can convince you of this. You need to convince yourself.