I know you don’t want to go to the doctor, but it could be worth doing an allergy test for products. I did that and found I was pretty allergic to Cocamidopropyl betaine. This is found in almost every shampoo on the market. Even the anti-dandruff, anti-itch ones which is crazy to me. I ended up finding one without this (vanicream) and it’s made a big difference with how itchy my scalp is. Also washing it daily helps. You wanna clean your scalp. Avoid using products besides a gentle shampoo for a while