welcome to the group and i will try to help with a couple of things, i know we we wear out at certain points in our lives. i have come to learn that slow steady approach to getting muscle back to the area you need it takes time, i go to the point of pain just a second or two and back off.
maybe try the exercise the way that i can still get the feel that its working but that's it. alternate group days, like today i do band exercises, was using a 20 weight band and because i got impatient i had to cut back to the 10 pd band. but since i backed off and took my time i can now know my limits and over the last three months have dropped a pants size. same band just more reps. lastly , drove semi approximately 30 years combined, over 3 million miles if you count my 4 years in Iraq, that would be no clue to how many shifts using a clutch with the knees, or hips getting up and down out of the truck or the trailer but i stayed in shape. mostly a keester load of walking. but it always came back to keeping the muscles around your bones in top working order or best as you can. ill be 69 next month and still just minor surgeries. I hope you can recover fully and get around like you want to. have a blessed day.