BenW,

Welcome to NeuroTalk.

I think you have two or three issues to consider.

You mentioned neck issues. These subtle neck injuries can be the cause of many of the symptoms you are experiencing. They can be very sensitive to bumps.

You also have a serious history with anxiety. This can magnify any symptoms.

The worst is how anxiety can cause the brain to memorize symptoms, often a serious cluster of symptoms that make one feel like they have a full head impact. This can be PTSD, Post Traumatic Stress Syndrome, a miserable condition where the brain can flash back to prior manifestations.

Add some unresolved vestibular concerns that can be triggered by movements and trigger anxieties and more and you end up in the misery you are experiencing.

The challenge with the neck injury is finding the gentle treatments than can help and then the discipline to maintain good posture during sleep and other activities and properly protect it during those rough rides.

One trick is to avoid sitting with an erect back and shoulders by relaxing the head and shoulder forward so the spine has more ability to absorb movement. Sleeping with the head and neck straight is important.

This subtle neck injury will have minimal physical pain. Just some stiffness.
But, the inflammation is can cause can trigger headaches and reduced blood flow and vestibular dysfunction.

I hope this helps you get a start toward some help.

My best to you.