I would suggest a trained and skilled CranioSacral Therapist, an experienced massage therapist and continue with the upper cervical chiro too. If there are no abnormalities, then it may be very tight muscles that radiate trigger points to your ear.

I still have problems with some pain in the back of my head from my whiplash, it took months before I could even sleep with my head laying back on the pillow, had to sleep on the opposite side. I'm getting started on more treatments this week. CranioSacral helped me the most so far (and the massage too).

Good Luck!