It could be from the progesterone. Have you ever been pregnant? Some women get really terrific itchiness when pregnant and then it goes away after that, and it's hypothesized that it's a reaction to the progesterone. You might talk to your doctor about this as a possibility, and see if there is any way to alleviate it (such as, maybe going on the Pill? just guessing there).
ugh, you've got it rough, haven't you?! Do you think that the itching before your period is due to yeast? I have heard of this happening in a cyclic way with our cycle. Vulvovaginitis is a chronic condition that is considered an inflammatory condition. Here's an article on it. https://www.medicalnewstoday.com/articles/322014#causes This article says one cause is reduced estrogen around the start of menopause or after childbirth. I would suspect it also can flare in a cyclic way around your cycle in general. I would most definitely talk to your doctor about this. You don't mention your age. I will tell you that I absolutely have mental health symptoms in a cyclic way related to my cycle. I always know I'm going to get my period in a week when I have three straight days in a row of raging anxiety and insomnia. Worse than it typically is. lol It's noticeable. As I've gotten accustomed to it, I have less anxiety about it. I used to dread it, would worry I'd be too exhausted or it would be awful. But now I kind of plan for it. And now that I'm even older, it's less so as I'm having fewer and fewer periods. There are psychiatrists that specialize in women's health and issues around our cycle. I think you have to hunt a little for them but there are at least two in my city. If it is TOO bad, I'd consider looking into that. A more careful approach of treating your adhd and any other mental health things like anxiety taking your hormones into account would be a good idea. Let me know what you think of this and we'll go from there.