My metabolism seemed to change about when I was 40. Before it was much easier to keep weight off. Afterwards, not so easy. I ended up gaining a lot of weight and was later diagnosed with diabetes. Of course breaking my leg and having it heal not correctly making snow skiing difficult wiped out a winter sport that kept me a bit more active was also a part of it. It gets discouraging when you restrict your diet to lose weight and gain weight instead. Maybe something like that has happened.
Another thing to consider is menopause and the hormonal changes that it caused.
Have you considered technical writing or ghost writing for technical topics? It may not be something that excites you but it may put your writing skills to work for reasonable pay. I am an engineer by both training and career. Writing was always one of those things I dreaded even though I don't really have a problem putting words on paper or in a computer. At times I sound like Yoda and can reread things many times and not see the flaws in the writing even though the technical logic is correct. There are others who could benefit from your skills and would pay for them.
Smart phones are the opiates of the masses of today. In some ways it makes me wish for the old days when friends were just addicted to street drugs.
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