Any permanent solution for my dandruff.

It is there since my childhood. I have been using medicines since my childhood days. Some doctor say that it is seborrheic dermatitis, some says that it is dandruff. I have used almost all the medicines. I am using shampoo like selsun, other lotions. Because of this issues I have lost almost 40-50% of my hair. When it itches badly ,  I do scratch my scalp. Because of that issues hair falls, Grey hairs is happening. Is it curable for permanent or not I wanted to know. Still I am using medicines to control that dandruff and hair falls also. And can I get back my hair on the scalp which has gone. Kindly, suggest me the best which I can follow and which should not be a problem if I am using. Because of this I could not trust on any doctors or anyone. I am using hair4you also to regrowth my hair. Nikhil Baral !!