Well it does sound serious, OP, but with any luck it will be manageable once you start treatment.
Like @weegiemum DH had CIDP, where the D is for demyelinating. The first sign something was wrong was an acute loss of balance well over 20 years ago. He was walking to work and he practically crawled home. Off to A&E we went.
Also like @weegiemum he has been responding well to treatment ever since it was properly tweaked, over 20 years now. You wouldn’t know anything was wrong to look at him. He is accumulating minor neuromuscular deficits very slowly but still in great shape compared to most retired men. I think he will be hill walking in his 80s at this rate.
Another big demyelinating disease is MS. As scary as that sounds, there are fabulous treatments now. My friend who has it is very athletic. It isn’t such an uncommon disease, either - we probably all know people who have MS and there is nothing in the way they go about daily life to indicate this. Relatively few cases have the bad outcomes that give it a scary reputation.
In fact, a friend who is a GP said that in her practice the doctors once had an idle convo ‘if you had to have a generic case of a common, serious disease, which one would you pick?’ Most of them chose MS because it is now generally very treatable, whereas they stayed well away from diabetes as they find it less predictable and more likely to have knock on effects.
Of course there may be other conditions. The terrible diseases like motor neurone disease are not demyelinating.
I feel sure your medical team will be following up with you soon, but will also understand if you chase this. Take care.