What can I use to get rid of flaky, itchy scalp?

I have itchy, flaky scalp. My friend is a hairdresser and said to stop using Head and Shoulders because it causes buildup. She said to use Moroccan Oil shampoo and conditioner. But I've been using it for weeks now and my scalp is worse. It almost looks like cradle cap. I asked at a salon and the lady told me it would take time to remove the buildup, but it's been weeks and it's not getting any better at all. I'm hesitant to go and spend a more money on stuff that's not going to work. Maybe the Moroccan oil works, but just not on my hair type. I'm just getting frustrated with the flakes and how itchy my whole head is. Any help is greatly appreciated.