hi Amber,,, i don't know much about cluster headaches, but i do know a little about oxygen (on it 24/7). i find that i can raise my blood oxygen levels by counting my breaths, slowing down and breathing more deeply; and with meditation. this lets me sit for a few hours a day without a hose up my nose.... a real pleasure... i hope you can find ways to relax the blood vessels in your brain (if that is part of the problem) ... the same way one can lower blood pressure, by relaxing and slowing the heart beat. often people need some kind of 'biological feedback' to learn these techniques. you can get a little finger machine, called an oxymeter, quite cheaply ($8 ??) at the pharmacy.

i wish you the best, finding a treatment, or even a cure~!