I am sorry to hear about your wife, and I hope for the best for you both.

Have you tried an activity you actually enjoy? I know that sounds a bit curt, but I gave up jogging for mountain biking and hiking, and now it is substantially easier to convince myself to get out and get started because I actually enjoy what I’m doing!

That shouldn’t have been as revelatory for me as it was, but the current paradigm is that jogging, gym time, or other monotonous activities are what we should be doing, and that really just sucks the joy out of physical activity.