Depends on cognitive situation but some things we did when my mum was in a similar situation -
Put together a list of things we'd do when she was up and about. Left it on table by the sofa so she could look at it / add to it when she wanted
I know tv seems a cop-out but I think if you're in a lot of pain and struggling to focus on other things it can really help. We sorted Netflix watchlist.
Talking Pictures (freeview) - shows old films and TV shows. Some stuff that's probably too old (1940s /50s) - but also lots from 60s/70s/80s. Think Z Cars, The A-Team, Magnum PI, Westerns, The Good Life etc. you can print out the programe schedule from their website.
audible account / audiobooks
Set up with amazon music and playlist of favourite songs. Got an Alexa device. She was really tickled by saying things like 'Alexa, play me (favourite song from playlist) etc'. Also Used Alexa for things like jokes, stories etc.
stack of books and magazines within easy reach.
Wordfeud (scrabble app on phone - can play people you know or a random opponent, so it's a little bit of interaction
Sorry, I know this is all quite basic stuff, wish I could come up with something more exciting. It's a really difficult time, I hope he starts to feel back to his normal self soon