You must, if you haven't already, accept your current body and it's limitations. Accept these changes, and live your life allowing yourself to rest, to adjust your activities and slow down with no apologies. Pushing to try to do more than your body should can end with you harming yourself. It's tough to do this, but we must put our new body first, helping next.
Sounds like you're doing this already.
Bless you, sir. elizabeth