Kathleen Anna .....
It sounds like you are doing amazingly well ..... walking, driving, shopping, etc. You are very wise to resume working part time for a couple of weeks before returning full time. My guess is you will be very tired at first, but you will build up more stamina as you go along.
I hope you can take breaks to just sit down and close your eyes in a quiet environment for 5-10 minutes ..... most of the time that is all it takes for me to be rejuvenated. Most, if not all, of us are operating at a higher energy level just to stay upright and deal with hearing issues. In my opinion, that saps our reserves more quickly and the brain needs a break to readjust/rest.
Not sure how much age is a factor, but it stands to reason the better you are physically, the easier the transition back to work will be. Just do not push it if you find it is just too much. Better to take a bit longer to let your body heal.
By the way, grocery shopping is still a very stressful thing for me ..... the narrow aisles, looking up and down the shelves, the noise, etc. I always sit down and rest when I get home.
Best thoughts. Clarice