Sounds like you're having a tough time of it with your CHs tyrannosaurus.
It is totally fine to rant and I'm sure it did you good too. It is something that many of us have done ourselves.
With the O2 are you using a non-rebreather mask and a high flow rate (15lpm with higher working faster)? Are you hyperventilating as this can speed things up too?
Sorry to hear that your doctor has passed away, but good that you've found someone. There have been multiple posts here about the Will Erwin Headache Research Center in the past (Google will find them for you). You can also contribute to the centre when you buy stuff using Amazon via smile.amazon.com, with it costing you nothing and Amazon giving just under 1% of the purchase price to them.
There are several people here who have used the Gammacore device with some good results. Again Google will find where people have posted about it (use the search box at the top of the page).
Have you got any CH preventives? These can cut down how many CHs you get.
Prednisione used as a taper (starting high and tapering off over about 7-10 days) is a good short term preventive. This could be good to get your CHs under control for the short term and to look after your job.
There are other longer term preventives like verapamil, lithium and topamax, which can be effective. Ask your doctor about them.
I'd also look at how many of us have had great success with using vitamin D3. Many have gone CH pain free (I'm going towards 6 years CH pain free). Read up about it at - Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to

or

.
Never had a song going through my head, although as a science fiction fan, the litany against fear from the Dune books often comes into my head at times of pain.
Quote:"I must not fear.
Fear is the mind-killer.
Fear is the little-death that brings total obliteration.
I will face my fear.
I will permit it to pass over me and through me.
And when it has gone past I will turn the inner eye to see its path.
Where the fear has gone there will be nothing. Only I will remain."
For good info about using seeds, mushrooms and similar try Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to

or

. They are the experts in that area.
Good luck with getting on top of your CHs and do update us with your progress.