Hi, welcome to the NeuroTalk Support Groups.

I'm sorry I know little about Chiari.
I did wonder when the last time you had any blood tests? The hoarseness is a red flag for thyroid and parathyroid also. A regular old Chem 20 blood test would show your calcium levels and lots of other blood chemistry. Thyroid would be done separately to that. At least it's like that here. Thyroid hormones affect the way you use energy. Parathyroid too and symptoms can include tiredness,muscle weakness and bone pain amongst other things.

PEM means Post-exertional malaise.

I'm not sure what is meant about the flu symptoms. Aches and pains. Headaches.

Jerking close to sleep is quite common. Myoclonic or hypnogogic jeck occur in totally healthy people as well although some meds or health issues might make that worse.

If you don't take your medication at the same time every day it might be wearing off a bit by the time you try to sleep. If that's the only med you take and you take in the morning then maybe ask the doctor if you can take it closer to dinner time so it's peaking when you want to sleep. You could at least see if that helps. What is that prescribed for in your case exactly? Depression? Pain?

The bugs crawling under the skin feeling or parasthesias can happen for a lot of different reasons. Blood sugar levels included.

I'm sorry it's all become so bad.

I know that ME/CFS can be that bad as to be unable to get out of bed.

I think I saw that Chemar showed you where the MG forum is too. I'd certainly do some reading in there.

Please be careful with lying in bed all day and night please. When I'm really ill and in bed a lot I get such sore legs and then I worry about blood clots.

It's nearly October again, so you've been sick a long time. Maybe get another opinion from an MD or go see someone more natural who may treat people with CFS or long Covid and has experience with post viral syndromes. They might have more knowledge about your myriad of symptoms.
Wish you well,
Let us know how you're doing,
Lara