Developed extremely dry patches on scalp

I have recently shifted to Mumbai in March,17. From around june onwards, started developing extremely dry flakes on scalp which started causing me irritation due to itching and it further resulted in blood while I use to itch it.. I am also losing a lot of hair from the areas affected with same. the redness has started spreading from the back of my hair to the back of neck. I always feel like itching my scalp. N the areas affected are the front hairline and mostly the sides and the back hair line. and since then itself I noticed considerable increase in dandruff up in my hair, the quantity being such so as it falls on my shoulders or my pants if i have wore any dark colours.. it's too visible.. always feel like itching my scalp.. very worried.. pls help