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!