I don't think you can depend on doctors and professionals regarding subtle neck issues and bumps in the road. You need to self treat with good sleeping posture and avoiding activities than require twisting and turning of the head and neck. Driving over bumps is much easier to deal with. Since these are the same bumps, you can plan on them. Lean forward in the car so the back of your shoulders are off the seat. You should be sort of hunched forward. This creates a curve in the spine that has more ability to absorb the vertical forces of the bumps. It might be worthwhile to get a springy pillow to sit on.

I do think your anxiety is making these symptoms appear much worse than they are. This is a common struggle with PCS and requires careful thought control to overcome. Maybe some counseling with someone who understand obsessive thoughts would help.