Best of luck with this and taking care of your dad,
@jowashington . Great advice has been given here and there seems to be a clear plan that minimizes the damage (recoup some money via credits, then stop paying).
If there is discomfort with defaulting, you can search and find many threads here on TUG where other posters share their experiences about when they defaulted. This experience is shared by many who refuse to keep being taken advantage of.
Very few of us are in a position to give legal advice, but we do use this BBS to share information,
My memory of reading thru some of those posts is that many credit agencies are simply familiar with people being scammed by timeshares and do not hold this as a serious offense. I believe many said they have called the credit agencies and gotten their accounts noted with concise details about the situation.
You may want to go thru some of those threads yourself.