You could have a headache from the rise in blood pressure from getting so upset.

What makes you think you will suffer a personality change?

It takes a very severe concussion to damage the personality part of the brain. Not just a bump.

If CBT did not help, it is likely that you do not believe that minor head bumps will not cause brain damage. If that is the case, I don't know how anybody can help you with your fears. If you will not accept the simple fact that the occasional head bump will not damage your brain, you have doomed yourself to these over-reactions to meaningless head bumps.

Are you willing to concede that these minor head bumps are not damaging?