Does the hair stick all together like you have the greasiest hair in history ? If it does then it is most likely product build up or some type of fungal infection .
Tea tree is anti fungal ,antibacterial and is great for those kinds of things .I used it straight when I first started using it .Big mistake .Always be sure to dilute it .
If those things fail and you cant see a doctor I would try to get your hands on some nizoral shampoo .It has ketoconazole in it .
Oh and is the "goo" at the crown of your head ? If so it sounds like what I had and the baby shampoo and dawn dish soap should work .
Let us know how it turns out