You've asked a question that has many doctors and scientists scratching their heads looking for an answer. Despite many animal and human studies, we still don't know what sets off persistent neck pain after whiplash injury. Like you, most people aren't seeking attention or secondary gain -- they just want to get better.
There's some new information that may help guide treatment for patients with chronic neck pain after car accidents. It's possible that the soft tissues around the joints in the neck may be strained and stretched during the accident.
Greater force or strain on the joint sets off special pain message units called nociceptors. Nerve or capsular injury around the joint leads to the release of inflammatory chemicals around the area. There is a heightened sensitivity of the pain pathways from the joint to the spinal cord and up to the brain.
As part of the increased sensitivity, there may be some "after shocks" or discharge from the nociceptors. The result is even more swelling, spontaneous firing of nociceptors, and more nerve pain.
Nothing shows up on an X-ray. Overstretch of the joint capsule isn't visible yet with any imaging studies we have available today. It's believed that high strain on the joint capsule damages the nerve pathways in the capsule. Persistent pain is the final result.
The future may bring better treatment for this problem. Right now pain relief can be obtained by destroying the nerves to the damaged facet joint capsule(s). Radiofrequency is used to heat up the nerves and destroy them. Sometimes the treatment has to be repeated more than once because the nerve endings try to regrow.