Tell me the treatment about white dandruff in my scalp?

I am Meenatchi. I am a village girl.For the past one year I am having white dandruff in my hair and also Itchy scalp. I tried lot of treatments. I used Head and Shoulders Shampoo twice in a week. Now for the past one month I am using Clear shampoo. I use lots of water to wash my hair. And also whenever i am taking head bath i use warmth gingelly/coconut oil massage for 20 mins. Even though, I am still facing the same dandruff and itching problem(I did not try Fenugreek seeds since I have wheezing trouble.) Kindly let me know the treatment for my hair. Homely treatment is much more welcome.