What is your avg daily pain level?
Does it increase with any activities?
What kind of work or activities do you do?

I see the mention of a past head/neck injury, did you ever have any (very good) phys therapy or chiropractic treatment for that ?
Past injuries can show up later in life as we age.

Head impact/whiplash can cause misalignment at the C1/ C2 also called atlas /axis.
Up C Spine - A New Approach - Sign / Symptom Checklist