I have the exact same problem, Lady Eagle. It was like crusty yellow buildup on my scalp, and I just couldn't stop itching! What you have is almost definitely seborrheic dermatitis. I went to my dermatologist and she prescribed Nizoral shampoo (prescription strength--even stronger than what they sell at the store.) It really cleared up my scalp. Now that the seborrheic dermatitis is gone, I use Neutrogena T-gel Extra Strength to keep my scalp flake-free. Though I no longer have oily, crusty buildup on my scalp, sometimes I do itch, though it's nowhere as itchy as it was before.

I would say that you should see a dermatologist or doctor if possible, because she/he will be able to prescribe something for you that will get rid of it fast. Also, I think that the CG routine may not be the best thing for people like us who have SD--if you wash your scalp with conditioner or regular shampoo, it will just make your problem worse. Hope this helps!
Black, shoulder length 3B

Law Student at Wayne State University, Class of 2010