I have a 15 regulator and I couldn't find my optimask (ordered new one it will be here day after tomorrow) so I'm using the rebreather they gave me with tanks. I can abort the attack, but it always comes back after 60 or 90 min. I've been staying on the O2. I even set my timer for 5 minutes after the pain stopped. Maybe that's not long enough, but I'm burning through the O2 quickly.I got no sleep all night and went tru a $15 tank of oxygen. My insurance won't pay for the oxygen either. I've read how to breathe,and it does stop,so why are they coming back? I don't want to do the caffeine, I want to sleep.