You may have trained your system to respond to bumps/contacts. You'd be surprised how the cascade of brain chemistry can snowball quickly. It's a Pavlov's dog kind of response. If a dog can be conditioned to salivate at the sound of a bell, any sensory stimulation can cause a reaction without a sound factual basis for the reaction. Early on, it may have been anxiety induced but with enough reactions, your body can learn to respond even when there is not a valid reason or anxiety. As an evolutionist, you should have learned about conditioned responses. But, maybe that is limited to animals, not plants.

So, deconditioning has great value.

FYI, It only takes 3 repetitions to condition a reaction. It take 7 breaks from the reaction to start to break the conditioning.

Maybe your EMDR training needs to focus on these head contact issues.

Don't get me wrong. I'm not saying your reactions are not real. They are very real. That is what makes them so difficult. But, you can condition train yourself out of the response.

Getting burned by a hot object becomes a conditioned response. The next time, the brain connects the pain to the sense of heat and retracts.

Your brain senses a contact and a perceived related danger and reacts as if there was an injury. It goes into a protect mode with the related symptoms.

I don't think you are going to get much better until you can stop this cycle. Empirical evidence shows this to be the case. A local brain injury PT sees this as a major factor that effects recovery. He told us the literature shows this to be true.

The simple physics of impact forces show these contacts to be of no measurable or calculateable value.