I have significant deterioration of myelin due to Multiple Sclerosis. It's painful, and causes all sorts of problems for me. Numbness, weakness, shooting pain, it sucks, and for me much of the damage is permanent. I have been getting IV Copaxone treatment that works to a certain extent.
How long do you have to be in the hospital? Do you have family or a friend to keep you company?
I don't have GBS, but I understand the problems you are having, as they are very much like what I've been dealing with. I hope this plasma exchange works. Just rest, and get better.