Dandruff??

Ok, so I have literally tried everything to stop the dandruff on my head, but it’s still there. I take warm showers (not too hot) brush my hair 4 times a day. I use a special shampoo and conditioner for dandruff, but nothing is working. Y’all I need help :,(( It looks gross. It might be because I have really thick hair, but that’s not very likely. I don’t know what to dooooo. It’s gross and itchy all the time. I’ve changed my showering schedule so many times. Pleeeaaaaaaaaseee helppp T^T