I'm Having Terrible Pain In My Head, Generally In The

I'm having terrible pain in my head, generally in the back of my head on the right side. I've been to the doctor and have had blood tested, showing no infection. I've been to the chiropractor for some adjustment and therapy on my neck (have a degenerated disk in neck), but MRI shows nothing. I'm taking ibuprofen for pain, every six hours, and sometimes icing, to survive the pain. Do you have any insight to what else to consider as the root of the problem?