Dad’s Quick Onset.
My onset at age 52 was very similar to your dad’s, as was the treatment: I had IVIG first, followed by PP because the head neuro @ Emory Univ. Hosp in Atlanta didn’t like my slow progression. Every neuro is different and has his/her own way of looking at things. The PP worked for me, whereas it didn’t look like the IVIG would.
Lots of good advice from Forum members. Neurontin/Gabapentin is the drug of choice for nerve pain. Your mom needs to get a handle on her finances quickly and POA is the best way. Your dad also needs reassurance that his is not an unusual case, though for him it will seem so, it always does. Finding someone to oversee his care right now is critical. His frustrations will only deepen if his needs are not met, both physically and emotionally. Is your mom able to spend large portions of the day with him, running interference with his caregivers? He needs that, at least until he gets totally weaned off the respirator and can be a little more in charge. Until then he needs a champion to do it for him.
As for someone to come see him, look into a local GBSFI chapter in the specific area of NY where he’s hospitalized. There shopuld be someone there who can help with that. It’s very important that he “see and hear” for himself that people do come back from this experience.