I second the upper cervical chiropractic - info @ Up C Spine

I went off my horse , hit head and was out for some amount of time..long ago @ age 15, no internet to learn about things then.. I was OK for the most part, but many years later I do think some upper cervical chiropractic back then would have headed off my chronic shoulder & hip & low back pain in middle age......
( if c1c2 become misaligned- the body will try to rebalance itself..)


If you can slow activities & mental activities down a bit, eat clean ( limit junk foods , alcohol, caffeine etc)...might get you past the plateau.

A really good chiro /PT can be very helpful, with soft tissue, alignment, muscle spasms, trigger points.