Hmmm... sorry to hear of your frustrations,
@DancingLion !
I really don't have an input calorie count part of the equation. And the fasting, well... I have heard enough indicating that it may not work for women, older women, especially if hormone issues, can throw things off worse. So I don't go for it myself. But I don't know enough about it to advise.
300 swings a day sounds like a very stressful program to continue for any length of time. Do you work up a sweat, heavy breathing, heart rate up? If so, it may be too glycolytic, too stress- and cortisol-inducing... can be counterproductive to your efforts.
How do you know you lost 5 more pounds of muscle? If your weight is the same, and you actually did lose lean mass, then you would have more fat. Do you see it and feel it; i.e. clothes fit tighter, slightly puffier appearance, etc.?
How is your strength currently, compared to July? How do you feel, especially regarding energy levels, recover, and stress? Do you have a doctor monitoring your hormone levels?
My gut instinct (on limited information) is to say, relax, de-stress, eat a little more, eat more regularly (no long periods of fasting), ease up the training to be less volume but more strength, and make sure the training is enjoyable. Then see if you are getting stronger and feeling better. Then take a look at the scale and BF% numbers.