dude, if you have any questions of a medical nature, feel totally free to message me. i've had every test you mentioned and about a thousand others over the course of my sickly-ass life, and medicine (allopathic/western and more natural) has become a huge passion of mine. meanwhile, total empathy and, check it: THIS TOO SHALL PASS.
ps - acute pain, while it blows, can be a good sign prognosis-wise. not that i know anything about what you're dealing with, but please badger your doctors to think along the lines of fungal/ parasitic things (in which they're not so well-trained) which are very treatable. just my two cents.
I started getting bad headaches a few years back. Same deal, they couldn't figure it out. Kept trying different meds, nothing. But the headaches would come and go. They still do. Now I just keep them kind of at bay with hefty amounts of excedrine and coffee. I know your pain, I hope they figure it out, yo.
My wife had blinding migraines several times a week for about a year once, but hers were brought on by a little thing called "a wicked car crash". I hope that you feel better soon!
You'll be in my fonder thoughts until all this si straightened out and you feel better.