I'm coming late to this discussion. I read through it all, so all I'll add is what I didn't see and what has worked for me.

Physical Therapy - in particular an exercise called the chin tuck. One type of migraine I get was caused by years of bad posture from sitting in positions to alleviate other neck pain. Doing the seated chin tuck hurt like the devil at first - almost impossible - and actually brought migraines & cervicogenic headaches on at first (to the point that I wanted to chuck it), but after several weeks/months, both kinds of headaches were reduced. Bottom line, some headaches may have some kind of physical misalignment involved.

I still get both kinds pretty regularly. Fortunately my migraines usually respond to Maxalt with coffee or some other potentiator. I've made my share of trips to the ER....

One thing I cannot do with any kind of headache is lie down; I must remain vertical/seated/sleep sitting up or they'll get worse rather than better.

Best wishes to all - IMO headaches are the worst kind of chronic pain because they're where you live (in your head)!