I don't have MS but understand the situation.
My suggestion is to keep the boat, move forward with your plans as health
permits and enjoy life.
If it were me I'd take the offer to see how your wife does on a cat. I do better strangely enough on a monohull
for balance. There are many things that can be done to help mitigate physical issues.
Becky's advice is spot on. Wearing a PFD
and staying on the boat. Perhaps a MOB alarm
and or PLB would add peace of mind. I suspect your Hunter
has a sugar scoop which also helps getting to the dink. If strength is an issue add snatch blocks.
It can be done. Feel free to send me a private message and I'll send my email
addy if you need ideas.