Sorry if I confused the issue with the pain scale. The only way I got any Doctor to take me seriously was to keep a Headache Diary, as although there is no pattern to them, it does show what I go through as far as that is possible.
High Flow Oxygen is usually prescribed to Cluster Headache sufferers, and at least here in the UK it is undergoing trials in London for Migraine. Please talk to your Doctor or Neurologist about this, it may be that there are some trials going in with this that may be available to you, as I say please discuss this with your Doctor. I am told that Oxygen is cheaper to prescribe than such as Imitrex injections!
The Oxygen tank needs to have a High flow Regulator up to 15 litres per minute, and to be breathed at 100% through a non-rebreather mask. When I have an attack I am usually on the O2 for about 20 mins. The O2 constricts the blood vessels in your head only, and not the rest of your body as do the triptans!
Oxygen will not work for everyone, I am just very thankful that it does work for me at the moment as I have nothing else to abort attacks!
Hope this helps, take care