Getting Old

I'm 58. I probably could manage aging better, but I'm not upset about getting older. I've made some concessions. I know I need to exercise more, but I just feel too tired at the end of the day when I get home from work. The main result is that, in the 13 years since I retired from the Army, I've added 20 pounds. I've leveled off at 190 and don't seem to go up or down more than 5 pounds, no matter what I do. That 20 pounds means I'm not obese, but I am overweight. I haven't felt any negative consequences except the obvious blow to my ego and a lack of stamina. All the weight is in one place - my gut. My legs, arms, butt...all normal. I just have this great belly hanging in front of me. I could get rid of it; I should get rid of it. But I don't.
I'm beat up. That's unavoidable after 22 years in the military. I have a bad back, bad neck, bad hips, bad hearing and weakening eyesight. I still function pretty well, though.
Since I got out of the Army, I've added some age-related limitations. I broke a wrist in Iraq. It didn't hurt that much, so I assumed it was a sprain. Now it's healed over and arthritis has set in. I have limited movement and residual pain now in my right wrist. I take pain medication for it every other day or so. It's really not that bad. In Tajikistan, I tore a ligament in my right thumb (what is it about my right hand?), so I can't really put any pressure on my thumb - I have trouble opening car doors and peanut butter jars. For both the wrist and the thumb, I have a brace I wear - all it really does is support my hand and wrist so I don't hurt myself by trying to do something reflexively that I can't do anymore.
With all these limitations, I'm still pretty functional. I can teach. I can travel. That lets me earn a living and support my family. I can still write. And I don't have any mental impairment - that's my greatest fear. I keep my brain active by writing, reading, doing puzzles. Alzheimer's doesn't run in my family at all, so I guess I shouldn't worry.
I got married and had kids late in life, so I plan on working until I'm 67. I'll still have one son in college, but my house will be paid off and I think the next car we buy (another Prius) will also be paid off by then. I'll have two sons grown up and out of college. I count on them taking care of their mother. She'll have social security, but she's 12 years younger than I am. She'll have the house and my 401k, so I think she'll be ok.
My biggest goal is to see my grandkids. I should be able to do that, God willing. All in all, I think I'm fine and have a lot to look forward to.