Most likely you have both a neck problem and a pcs.

When "moving" your neck brings on symptoms it is usually because the neck itself is the cause of symtoms , more specifically the cervical vertebrae.

Whe concentrating as in driving gives you a pressure-type of headache it is the concussion (brain fatigue! usually indicates that you need to rest)

In real life though, it is not always that clear cut and some symptoms do overlap.(different types of headaches can occur altogether!).

in any case seeing a good chiropractor can be very helpful.