♥ I definitely can relate to your search for relief. When my doctor told me that there might be nothing that would do the trick, that we might have to try different things, I told him that if he suspected that rabbit poop would ease the pain, I would eat it, ANYTHING to find relief and allow me to function.
♥ Lisa said, ". . . the cause of the pain is generally unknown". Let me add that there are a multitude of causes, too, so what causes yours might not be the cause of mine. Trigeminal neuralgia is a symptom of something else going on, not a condition in itself that needs curing. Although the pain DOES need curing, no doubt about it. Injuries from car wrecks or dentists cause the pain for some people, a tumor might cause it for some, shingles might cause it, a swollen blood vessel sharing the nerve foramen might cause it, and multiple sclerosis causes mine. All this is to say that maybe you can relieve the pain but a surer bet will be to relieve the cause if it can be determined.
♥ The B vitamins are nervous system nutrients. If you think vitamins will help you might want to start there.
Muscle relaxants (Flexeril helps me) might help more than you would imagine; the nerves run through and over muscles, and to release muscle tension is to release tugging on the nerves or to release squeezing the nerves.
♥ Knowing what I know now about MY personal struggle with TN, I would advise anyone and everyone to get an MRI to see if they might have MS and not know it. It's not something that doctors look for, even when they think options have been "exhausted". No one looked for it in me until I went blind, but when I did, the doctors looked, and lo and behold, there was the cause for all the weirdness I had been experiencing.
♥ The list of meds you gave seem to me like they would put Godzilla out of commission. I have tried narcotics, and they did not even touch this pain. I am sorry to read that your muscle relaxants don't seem to help.
♥ But you asked about vitamins and supplements. As I mentioned, B vitamins are nerve vitamins, and my neurologist has given me B12 to help with that, and he has given me vitamin D because people with MS tend to have VitD deficiency. Other supplements have had no effect at all on me, not even bad effects. I have not tried homeopathy so I can't speak for that.
♥ Good luck with your search for relief. Thanks for telling about the surgeries that did not work - I was going to ask my neurologist to cut something or remove something just to try to get rid of the pain.