Nana are these new things or has he always done these things?
I have observed that many men are basically bored once they retire and spend far too much time sitting on the sofa watching Netflix or YouTube!
I have started encouraging to the point of nagging my DH to take some b. exercise instead of sitting on his backside all and every day.
It is uphill work, but at least on the days where it doesn't rain (yes, I know they have been in short supply) I get him out on his bike for an hour or so and even to do some shopping whilst out. When it has poured for more than one day, I send him to walk up and down stairs three times without stopping, (Strengthening exercises for his legs)
It is slowly but surely paying off. (And we are still married!)
Is there a health reason for him wanting you to do less? If not, go ahead and invite family and friends as you miss them, and let him like it or lump it.
Could you not have picked up your sister from hospital, instead of asking him. Surely you knew how he would react?
Obviously, there could be other health issues than too little exercise, and sleeping in the daytime, but I found it easier to nag my dearly beloved husband into getting off his backside now and again, than into making an appointment with his GP.