Very sorry to read this, brs'. The only substantive suggestions I can make are (1) to start the vitamin D3 regimen ASAP (http://www.vitamindwiki.com/tiki-download_wiki_attachment.php?attId=7708); (2) to be sure that your oxygen system is optimized (at least 25 lpm flow rate and the "ClusterO2 Kit" mask that is designed specifically for CH); (3) perhaps to try melatonin at night, starting at about 9mg and working up as needed); (4) to try Benadryl 25mg 3 times a day and 50mg at night (probably not taking both Benadryl and melatonin at night). Severe CH outbreaks seem to sometimes be associated with allergies, even if you're not aware of those allergies; and (5) try an energy shot such as 5-Hour Energy at the first sign of an attack.
#3 - #5 seem so trivial in the face of what you are dealing with that I have been hesitant to bring them up, but it's what I can think of. Wish I had more, and I hope others will.
Do you think it's possible that you have developed another kind of "headache"? It's so rare that none of the standard things are working -- Imitrex, steroids, O2, etc. There is the CH "lookalike" condition, hemicrania, that is not usually successfully treated with those things but is responsive to the drug indomethacin. That might be worth looking into. There have been people here who have both CH and some form of hemicrania.
I hope things get better for you soon, and again I'm sorry to not have more to offer. The D3 regimen has been very effective for many people, and the fellow who formulated that regimen, Batch, is a great guy who would be completely willing to help you with doing it.