Siegfried, would it be worth it to try any of these supplemental or alternative treatments?
https://americanheadachesociety.org/wp-content/uploads/2018/05/Hemicrania_Continue_June_2015.pdf
"There are alternative medications that can replace indomethacin if needed, but unfortunately they are not perfect for treating hemicrania continua. Sometimes they can supplement a lower dose of indomethacin if that is all that is tolerated. Melatonin is a natural hormone with a chemical structure similar to indomethacin. A few people have had a complete response for their HC with melatonin alone, but more often they have been able to get relief with a lower dose of indomethacin while taking the melatonin. Alternative medications that may replace indomethacin, if it cannot be taken at all, include gabapentin, topiramate, verapamil, and cox-2 inhibitors (anti-inflammatories less likely to cause stomach bleeding). Even onabotulinumtoxinA, commercially known as Botox (Allergan, Irvine, CA, USA), has been tried in cases where other options failed or were not tolerated. Nerve blocks, injected at the back of the head on the same side as the pain, can be performed with long-acting anesthetics. Rarely, a nerve stimulator is placed with leads extending over the back of the head or neck, providing continuous low-level stimulation to the area."