Constant pain is the pits, isn't it? You don't want to mention it because people will think you're crazy, but if you don't mention it, how will it ever be different for you?? Here's a couple of things you might look at:
certainly Multiple Sclerosis, POTS, fibromyalgia, Sporadic Hemiplegia Migraine.
ALL of the things you listed in the first paragraph can be part of the Hemiplegia migraine aura, then the migraine to draw it all together. A migraine like nothing you've ever had before. Non-epileptic seizures could be the shaking, weakness and co-ordination - and that's an aura for the Hemiplegia migraine. Vestibular (eye) drooping and vision changes are in there as well.
It all rather looks like someone might be having a stroke or TIA, but for those of us with HM, we know the difference.
I believe the Mayo Clinic have a really good headache clinic - give them a call - https://connect.mayoclinic.org/discussion/hemiplegia-disorder/