How long have you had the problem?
Can you think of anything that might have changed or been introduced into your life at about the same time the itching began? For instance, did you change laundry detergents or fabric softeners? If you towel dry your hair, these could be factors. Did you start any new medications, or start taking any new over the counter products? Did you buy a new hairbrush?
I had a problem with itchy scalp a very long time ago. In my case, I was reacting to hair care/hair coloring products. I found it helpful to wash my hair often with a very mild baby shampoo. These products contain non of the irritants often found in shampoos for adults.
I'm sorry you have to wait so long to see a doctor. Is there no way you could get to see someone, like a dermatologist, any sooner? It is a very annoying problem and it would be better if you could get relief sooner.