Woody,
Don't give up ! Just do a little at a time, there are no rules to say that you have to stand at the lathe for hours at a time.
I have a 'heart condition', couple of operations and a pacemaker, I just adjust my time, if I feel like doing a bit (of turning !) I do, if I don't then well, I leave it till the next time. Best of it is you can just walk away from the shavings etc and clear them up next time, unless of course your lathe is in the lounge !
Also you can always pass on all you accumulated skills to others who are just starting out.
It's time for you to look at things,we're fortunate we had warnings about our health and can make adjustments. Lot's haven't been given that opportunity.
Take care and keep on turning !
Best wishes,
Bob.