Newbie again..and in my late 50s

Menopause per se tends to be less of a factor than is a common tendency to have become less active over the decades, and to have lost muscle mass along the way. (It may not be true for everyone, but my lifestyle in my 20s had a lot more physical job, more walking/biking transportation, more active play in social life, doing home improvement/maintenance tasks myself that I'd now hire out, and more, compared to now at 67!) This can all be pretty subtle and gradual, so we don't much notice as it's happening.

On top of that, gaining weight tends to make moving harder and less fun, so we may do less of it; and doing less of it can accelerate that gradual muscle loss.

The good news is that that means much of this is not "metabolic doom", but instead things we can control, or at least influence. The key variables are what we eat (especially how many calories), and how much we move (not just exercise, but daily life stuff).

As context, I lost weight with MFP back in 2015-16 at age 59-60, from just over the line into class 1 obese to a healthy weight, and I've stayed at a healthy weight for 7+ years since . . . that, after around 30 previous years of overweight/obesity.

I understand what you're saying about health limitations on exercise. What I'd say is that any kind of moving more is going to be a help, and we can seek out things that are more doable. Too many people think that some kind of extreme, even punitively intense exercise is essential for weight loss, but that's absolutely a myth. Exercise burns a few more calories (so we get to eat a little more while losing weight at the same rate), and is good for health and functioning, but it's possible to lose weight with zero added exercise.

For me, it helped to experiment and find things - types of exercise - that were compatible with my pre-existing limitations. As I got fitter and lighter, I found that some types of limitations (like pain from my arthritis and torn meniscus) were meaningfully reduced, so less of a limitation than formerly. I started out gradually, with manageable exercise, and gradually increased it to keep a little bit of a challenge in the picture, without making the underlying conditions worse. For me, things like yoga were a good starting point - and we don't have to be flexible to do it, we just need to find the right type that fits our starting point. Yoga and stretching is ideal for people who aren't flexible, because it can gradually improve flexibility and mobility.

Some people find water exercise to be a good starting point, because the water supports some body weight. If you have access to a pool, or a lake in warm weather, that might be an option. Even walking in the water is useful: It doesn't need to be some big formal thing. That said, there are pool classes for people with arthritis in some places.

If you're able to walk, even short distances at first, that can also be a good starting place. Another option would be seated exercises that don't over-stress your back: There are quite a few YouTube videos of seated exercises for seniors or new exercisers that might suit you, though (with apologies) I don't have specific ones to recommend.

Since you have a number of pre-existing physical conditions, is there any chance your doctor would refer you for physical therapy, where you could learn exercises that would either improve symptoms, avoid further damage, or even let you make some strength/fitness progress? I've found physical therapy helpful with some things like that.

Another thing that can help, gradually, is consciously increasing daily life movement of any type. (Many of us have gotten more sedentary or physically placid over the decades . . . .). There's a thread here where many MFP-ers share their ideas for doing this:

http://community.myfitnesspal.com/en/discussion/10610953/neat-improvement-strategies-to-improve-weight-loss/p1

There are quite a few women here who've lost weight at menopause ages. It can work. It takes persistence, patience, maybe a little bit of wiliness . . . but usually we know ourselves pretty well by this age, so that self-knowledge can be a help.

Cheering for you to succeed - it's so worth it!