I have extremely think shoulder length hair and no matter if i wash my hair every day or leave it several days inbetween washing it i always end up with a very irritable itchy, flaky, dry/grease scalp. I have tried allsorts of different shampoos both with sulphate and without but nothing seems to clear it up. I have had this problem both with long and short hair for most of my life. Can you please suggest something that may help. Thanks