Since you rightly say there's no separation between the physical and mental, I hope you are able to take care of yourself in areas you still can do...this is how I make sure to live my life that has begin to get issues of old age, being 80. Indeed it becomes even More important when some other problem creeps us in us, physical Or mental. Our beings are complex and unless I had an accident and broke my arm, I'd not know what needs fixing most; most other things are not that simple: When I was hit a year ago by a car which slowly started to move while I was still crossing the road, I was able to fall rolling my body with just a bruise. It was Not the fault of the driver but of the Sun which was in his line of sight. Could I have end up with more serious consequences if I was not in reasonably good shape? Very likely. So let's do our part that we still can...and leave the rest to the universe, as I tell myself. wholesome food, exercises that make body limber and strong in strength and stamina help with good sleep too. And I hope you have a few friends to share your fears and funny streaks in life. I look for them at every opportunity. They are Healing because they offer what no other human connection -- coworkers, family neighbors provide.
Good luck!