A car headrest is designed to have enough give to prevent a concussion or injury except in the most extreme circumstances. So, unless you hit the headrest with enough force to break it, you did not injury yourself.

Your biggest need is help with your anxiety. Anxiety can mimic all the symptoms of a concussion.

Try to remember that just walking, especially up or down steps, subjects the head to far more force than any of these bumps and your brain tolerates these foot plant impacts hundreds of times a day.

It appears you have become so anxious about touching your head against anything that head bumps that you did without even thinking twice are now pushing you over the edge.

Hits happen. The brain tolerates then. Give yourself a break.