I'm 18 male when i shake my hair hair falls out , there is dandruff on my head doctor prescribed me shampoo called nazol but nothing changed after use?

Nazol is for fungi: I suspect you actually have telogen effluvium or less likely alopecia areata. Neither of these is especially treatable; the first eventually self-cures, the second affects one of my male colleagues who loves being totally smooth. Your best move now is to hit the physical fitness circuit really hard. It'll make you healthy, and you'll look fantastic -- you CAN control this. Best wishes.