Years of Scalp Trouble!

So im using ManCave Caffiene shampoo at the moment and after having a bath and sleeping i wake up to yet another day of being itchy particularly behind my ears round the back of my head and lots of little white bits come falling off if i itch!

Im here hoping for some possible solutions..

Does leaving hair damp before bed have an effect? Are there some better (reasonably priced) shampoo available? Is there anything else that contributes to this problem?