What Causes Chronic Headaches?

I am a 30 year old female. Height 5 6.5 . Weight 212. I have a history of headaches over the last two years. I have seen my pcp who referred me to a Neurologist. I have taken Relafen, Amitriptline, Flexirill and Diclofen for my headaches. though not all at the same time. Today I began seeing bright spots as I had been looking at the sun. Shortly afterward I developed a headache on the right side of my head only, down to my clavicle, including temples. My right eye is painful and sensitive to light and eye movement. I do not grind my teeth but my jaw seems tight. I have a history of TMJ as well. What could be causing the frequent headaches. I have had multiple scans including CT and MRI/MRA. My neuro says its stress related but even at my most relaxed, I get headaches.