Beau lines, hairfall, scalp. About this!

I am having nail ridges and hairfall both from past 7 years, nail ridges are on every nail on hands and feet . Hair is falling from everywhere even my beard and also from eye brows, having receding hairline , i m also having dandruff like thing which i think is not dandruff, a white thing salt like grains and powder also , this come from scalp, beard ,eyebrows . Hairs above ear also fall because of this dandruff like thing, same is for eyebrows. I tried biotin 5000mcg but it didnt work for me, no improvement in my nails and hairs. And sometimes ma nail easily gets detached from nail bed . It can b because of psoriasis but i dnt knw No doctor takes it seriously, they just prescribe fanastride, and what about my nail, both thing are somewhat related to each other. Please help me about this