Your hair fall seems to be due to excessive dry scalp you are having. This dryness could either be due to scalp psoriasis
or seborrheic dermatitis
. The definite diagnosis can only be made after examining your scalp. In the meanwhile use a ketoconazole
and tar based shampoo on alternate days over scalp. Apply steroid and salicylic acid
based lotion over scalp in night. Do it for 15 days and let us know the response. I would also suggest you to send pictures of scalp so that a proper diagnosis be made and further treatment can be suggested.