Living in the present is all very well and good, but if you are anything like me, Margiknot, if you do so to the extent of not considering the future, your peace of mind will suffer.
You and your DH have had a nasty shock and need time to get over it, so the advice not to do anything too hastily is sound, as is the advice to look quietly into things on your own.
It entirely depends on your financial situation whether an old house that needs a lot of maintenance is a feasible proposition. It is if you can afford to pay for the work that has to be done and to heat the place properly, but if you cannot afford help and your DH has formerly done the work, then obviously it is a completely different affair.
If you have not already done so, make or revise your will.
Discuss with a solicitor, chartered accountant or your bank how you will stand financially if your husband predeceases you, and how he will stand if you predecease him, plus what your son's situation will be financially in either circumstance.
It is not morbid to plan for the future, although none of us like doing so, when the future we are talking about is widowhood!
Will your son need a guardian, when you and your husband are no longer able to deal with his affairs?
It may seem hard-hearted to move your son into care now, but it might well be the best possible thing for him, and it would give you a realistic chance of moving to a smaller, easilier kept property.
I too am facing the propect of a husband being frailer than we had envisaged six years ago when we bought our present house and what we can or should do about this.
Obviously, neither you nor I would dream of making it too obvious that we sometimes wonder if widowhood is to be our fate. The longer our husbands are convinced that they can and will regain their former health the better, but to me that does not mean we should totally ignore the little voice in the back of our minds that says, "How will you manage if...?
I have found the best way to shut that sneaky little voice up, is to make a few contingency plans, so I know I could perhaps do A, B or C if it becomes necessary.
I have no experience in providing care for an adult who cannot care for himself, but please do get professional advice about this.
One thing, I will permit myself to say is this: change is always difficult whenever it comes. It just might be better to move your son into a permanent assisted living facility now, rather than later.