I have had CH for about 40 years.
The docs do not know what causes them; in my case it was not stress that started them, and it certainly is not stress now.
I have tried acupuncture, all the usual pain killers, physiotherapy, all without success.
I have been prescribed Pethidine on a couple of occasions as a last resort to relieve extreme pain, but it is not the sort of drug one wants to use regularly.
Then came Emigran (Sumatriptan) which I take as an injection, works like magic, can go from a screaming raging CH to normal in 5 minutes.