It looks like on your general information post, you didn't want medical advice, so I do apologize if I'm stepping on toes here, but in another post, you mentioned Trigeminal Neuralgia.
My speech therapist actually got into her line of work because of experiencing face/head/neck neuralgia herself, (on top of being a singer) and so her practice includes manual therapies on top of the more typical speech therapy practice. (apparently its more popular in speech pathology training in the Boston/New England area, so not sure if its as accessible around you)
I suggest looking into manual therapies for treatment, and speech therapists may be a good place to start looking for it. Its made a world of difference for me and my own SLP.
Also, I'm a little curious about Cyclic Vomiting Syndrome. It'd be a bit of a long shot in your case, but if you feel the strong urge to bathe in really, really hot water, tell your specialists- its an obscure one, usually associated with children and gets written off as a form of migraine in adults.