scalp condition

Hey I'm a 26 year old male who is getting some fairly bad hairloss. in adition to this I've, for the past 3 years, suddenly developed an uncontrollably itchy scalp and severe dandruff. When I scratch my scalp hard enough a soft, waxy substance homes off, or tiny salt-like grains, along with a lot of hair.   None of the shampoos lke nizoral (1%) or Tgel/Tsal seem to help. I'm wondering, first of all, what this is....I have generally good hygenie and have never herad of such a problem. Secondly, I'm wondering if this might be a major contributing factor to my hair loss.