I dont have MS, my wife does. I spotted your message because I had Shingles on the trigeminal nerve starting in July 2016, 3 weeks after completing a course of prostate cancer radiation/chemo treatment. I then started the mother of all toothaches which my dentist did not associate with shingles. The correct diagnosis came from my local A&E.The GP said mine was a classic case of the Herpes Zoster awaking from its long sleep following chickenpox when I was 11. I’m now 77. The GP finally but only after 3 weeks, prescribed 20mg Amitryptiline and that initially at 2 tabs per night, reducing to one, gave me uninterrupted sleep and was my salvation. People in some other countries dont get chickenpox because they are vaccinated as children but cleverer people than me decided thet Brits are made of sterner stuff so if the MS Soc is still around in 100 years time there may still be people getting the sting in the tail of shingles- trigeminal neuralgia. You are right -there is simply no pain as bad. Big Pharma is not going to invest its millions in Herpes Zoster treatments when this complaint no longer exists in North America for example.
I later bought (£175) a booster vaccination because I am the wrong age to get one on the NHS. You cant get paid for boosters from your own GP due to some arcane NHS rule, so I travelled 30 miles to Birmingham to get mine. That was after I finally found a member of my GP practice who would come off the medical fence and say I should indeed have a booster.
I deeply sympathise with what you are going through, not that that’s much consolation.
It is said that herpes zoster attacks when the conditions for it are perfect. Those are when immunity levels are very low.