T.F.
I am sorry you are going through this.
Unfortunately, I believe that nothing can be done until "he" realizes it needs to be done.
Speaking as someone who recently lost my husband very suddenly, it is a complete shock and sometimes I have a hard time getting myself out of bed to do my daily routine and get out of the house. It still feels like yesterday that my husband just dropped dead in front of me at home and it happened last October. New Years Eve 2015 would have been our 27th anniversary and we had been together 30 years.
How old is he? I am assuming retired. He needs to be active. As strange as it seems, my 21yo daughter notices if I am not getting out enough and she makes plans to have a meal, shop, etc. She is pretty smart because she knows I don't turn her down to do anything because I keep in the back of my head that someday she will be too busy for me and I won't get that opportunity.. possibly (unlikely but possibly).
What about grandchildren? A senior center?
It is very hard losing your partner. I am in grief counsel with some people still there from losing a partner 4 years ago. I am one of the newbies. Some people just can't go on without their partner and others have a complete reversal and marry the first person to come along because they cant stand to not be married.
There is a man in his late 70's in my group and his wife died in December 2015. I can see him declining every time we meet. I know he babysits his grandchildren and he daughter is doing her darndest to keep him busy. His 50th anniversary would have been in 2016.
The counseling program we are in is a non profit through our city. It costs nothing to participants. It is one area of my city that I am giving back because I see how well it helps people.
Best wishes to you