I will turn 53 years old in a few weeks and have had myriad health issues the past year......Thyroid cancer and resulting surgery, pinched nerve in my neck requiring physical therapy (likely from degenerated, bulging cervical disc), increasing blood pressure which for many years was consistently 120/80 but is now 130/110, worsening eyesight to the point I now cannot read much of anything without my glasses, all of this on top of the chronic IBD/chronic sleep issues I have always had and for which I take a plethora of medications. It is disheartening, but I realize that the aging process eventually takes its toll on all of us. I try to look for silver linings- one is that I can still perform sexually although not as well as I once did or would like to. Another silver lining is that I still look pretty good for my age, and another is that I still can do my job as well as ever despite all of these issues, and I feel like I am productive in what I do, which is important.
However, I do get the same feelings of despondency especially when thinking about the future and my parents etc. but I fight off those thoughts and try to enjoy life as much as I can while I can. Generally I am successful in fighting these mental issues with physical activity, but I can understand how, if physical activity becomes restricted and one has more time on their hands, it gets that much harder. Counseling/support groups with others with like issues helps. Good luck.