So sorry, I can relate to some of it. I guess A-fib is the kickoff for Long Covid which I had Feb 17, 2024 after seemingly recovering from COVID. Apparently 3 days in the hospital is the norm which I too spent 3 days in the hospital.

When I was released I thought that was it and I'd be up and around in no time. I have struggled to go back to walking but must do it in increments. Instead of the 45 minute brisk walk I did daily pre-covid, it's now up to 10 minutes 4 to 5 times a day by pacing in the house. I also life 5 lb weight once per week.

Occasionally, we have date night in with dinner and a movie. I do cooking from a chair in the kitchen and take frequent rest periods. I have the keyboard in my lap as I am counting this as a rest period. I'm sure your LC experience is much worse than mine, and I hope you are able to make little changes to build your strength back.
Yes the brain fog is awful. I don't remember things. I write myself notes in order to leave the room to let myself know that at such a time I must turn off the stove or oven. I never needed a cane and still don't, but I now have one to lean on while walking because I seem to be able to walk longer with it than I do without it.
Of course, 3 of my grandchildren are over 18 and sometimes drive across town to see me.
My poor husband has to do many of my chores. He has enough of his own.
I hope something here helps in some small way. I need to go rest.