My mom just retired from direct patient care nursing last year, she's a little older than you. She plans to come back to nursing in a different capacity, leaving the bedside/clinic all together. Are you still wanting to provide patient care, or take on a more administrative role? My mom did the latter when she felt that the bedside was physically too hard on her. She is looking to work for an insurance company (she's a NP) doing chart audits in a year or two. I also know of RNs doing telephone triage for insurance companies as well.
Some patient care care areas that I can think of that may be a good fit for an experienced med/surg nurse like yourself:
1) wound care nurse (could be hospital or home health)
2) dialysis clinics
4) PICC line nurse
5) nursery (babies aren't heavy but you may still be busy on your feet a lot.)
6) urgent care center doing triage (some of the ones here are open 9am -9pm, some are 24 hours, it all varies)
7) lactation consultant
You could also do a combo of a few things. Such as work PRN 12 hour shifts in your favorite area, and then work part time doing something non demanding such as educator, case manager, etc.
these are all things my mom and I discussed for her transition/retirement plan. Hope it helps & best of luck to you in continuing your journey!