How do you tell your elderly neighbor that you can’t help him anymore?

How do you tell your elderly neighbor that you can’t help him anymore?

"Over the last year we’ve helped out our 85 year old neighbor by getting groceries for him, picking up his prescriptions and other odds and ends so he wouldn’t need to leave his house.
He got his second shot of the vaccine and he’s still expecting us to help. It’s been difficult to find time to help him because we’re getting back to work and busy with the kids. What do we do?"