I was in a rear-end mva three years ago and never been the same since. I can feel confident in saying that chiropractic combined with massage therapy
has been helpful -- especially cranio-sacral therapy, myofascial release
, trigger point.
Find a credentialed CS therapist or a local cranial-sacral institute in your area for further care. Preferably someone who is trained in the above.
Having a trained Rolfer work on you could be helpful too.