What Is The Treatment For Severe Hair Loss?

i have hairfall from 2years & use 2 have dandruff, i used nizoral 4 2months & now i dont have dandruff but still have hairfall. what should i do?. i took vitamin E capsule for 1year & now am taking multivitamin tablets but no imporment in hairfall. is there any shampoo are tablets for hairfall? please tell me!. every day i get 150-200 hairs in my comb.