I’m afraid I haven’t got anything nearly as constructive to say as Louise, but I am rooting for you and hope you can find some space in your life to focus on yourself and the changes you want to make.
I probably have the opposite lifestyle to you as I am retired and through choice I don’t have any children, so other than my very bossy cat I have few demands on my time. My friends in the village though, who do work, run a home and look after a family sound more like you. My observation of them is that they seem to take on all sorts of responsibilities that they don’t need to or at the very least could choose not to but feel pressured to do so by a variety of factors. This leaves them very little time for their own self care. I know from my own experience that this is not sustainable.
In my 30s I worked for a New Zealand company installing Pathology IT systems into hospital laboratories all over the world. I seemed to spend half my life on the road, living in hotels, eating and drinking too much, not getting any exercise and basically just working, sometimes from 6am until late, 6 or 7 days a week. I didn’t even have time to get my haircut or go for regular health check ups. I gained over 100lbs, could hardly walk more than a few hundred yards and was drinking like a fish. Eventually, I had a breakdown and had 3 months off work.
The sobering thing I learned by that experience is that the world didn’t fall apart just because I did. It kept going just fine without me.
So try if can to you prioritise yourself and your needs Jane they are every bit as important as everyone else’s.