thin and damaged hair

my hair used to be pretty healthy till the last yr,from this one year i`ve been facing problems like falling thinning and damaging of hair.i`ve been consulting a few dermatologists but invain.the only solution suggested is the intake of essential nutrients therefore i`ve added vitamins and mineral supplements to my diet for the alst two month along with the use of anti dandruff products but it just keeps on getting worse.my hair is of shoulder-length i can`t think about a hair cut right now as none of the hair cuts would suit the fuzzy texture of my hair.i`d be highly obliged if i`d be enlightened with some suggestions for texture improvement and rapid growth of hair.