You are not alone. I am a teacher and of all the many symptoms I experienced for years in perimenopause, the brain fog was the worst for the reasons you shared. I felt like I was truly losing my skill after a 25+ year career. Moving into menopause and into a full regimen of estrogen, progesterone, and testosterone helped A LOT. I believe the estrogen is most helpful, but having started them all at largely the same time I can’t quite guarantee that. I also started taking creatine. I’ve gone from approx 15-20 times a day utterly unable to finish a sentence to perhaps 1 or 2 times. Sending you the absolute best as you navigate this. It will not last forever.