Ha. Well, it turned out I didn't have occipital neuralgia. I had Lyme disease. (That's actual Lyme disease, not the controversial --- and quite possible non-existent --- "Chronic Lyme", that you can read about on the Interwebs.)
And I found out I had Lyme disease when I had to go to hospital after a couple of TIAs. January was a lot of fun.
So now the Lyme is gone
(after four weeks of intravenous antibiotics), and with it the headaches and all my other fatigue and "minor things suddenly not working" symptoms. I'm taking 100mg of aspirin a day to try and keep the TIAs away (they are not a common symptom of Lyme, but according to my neurologist the Lyme had started to attack pretty much every part of my body that it could, so anything is possible). And I may have a "type 2.1 atrio-ventricular block", due to the Lyme, but that may well fix itself --- in any case I have no cardiac symptoms. And just to top it off, I discovered I have a congenital patent foramen ovale (aka hole in the heart), which apparently is not serious despite the name!
I spent 16 days in hospital. Even in France with its mostly socialised healthcare system, that costs $1,200 a day for the basic bed fee. I'll never see the bill, but I'm guessing there won't be much change from $30,000 after adding in two MRIs, one run each through the gamma camera and PET scanner, etc etc. (My co-pay: $0.
)