I'm very sorry to hear that you are going through this stressful time! I agree with your doctors
so far that Guillain Barre syndrome is high on the list of possibilities. Basically, this is a condition in which the nerves in the periphery of the body get inflamed, generally as a result of some sort of viral infection, although there can be other triggers as well. The spinal tap you had done is also consistent with Guillain Barre syndrome, because in Guillain Barre there tends to be an isolated elevation of the protein levels in the spinal fluid. The hives/rash that you have might also be consistent, because many viral infections that trigger Guillain Barree might also trigger this kind of localized skin reaction. The symptoms of Guillain Barre do include numbness and tingling
and muscle weakness. The symptoms tend to get worse before they get better, and they tend to ascend the limbs. Therefore, being in a safe place such as the hospital is a great environment to be in, because your doctors will be able to follow you closely to see how your symptoms are doing. Input from a neurologist
would be very helpful, I think, if you have not had a consultation with one yet.