Itchy scalp is really startin to get to me, any suggestions?

Ok. I have had an itchy scalp that has bothered me ever since i hit my teenage years. It use to be that it would just flake a little but only itch ever so often. I'm in my mid-twenties now and it's like a whole different ballgame. The flakes are unbelieve in their amount, my scalp itches consistenly, and I have sores all over my scalp that get as big around as quarters. I can wash my hair then about two hours later the itch is back. Through the years i have tried different shampoos and conditioners but if they gave any relief it only lasted for a couple of months. Any suggestions or help is appreciated. Thank you so much in advance.