At our age that happens. We don't have the energy sometimes to rebound quickly, or absorb more problems or grief without it taking a toll on us. Life can become overwhelming at times, especially being alone in my mid fifties. But I remind myself that I am blessed - I have three healthy adult children, I've had relatively few real health problems, and though I live paycheck to paycheck I'm not without food, shelter, or car (nor a bike, skis and computer

). My ex always saw the glass as almost empty. I see it as almost full.
If something becomes a chore, like biking, it's time to take a break and revitalize. Pursue other interests, visit places by car, whatever gets your interest going again. And think about getting a medical check up, if you haven't recently.