For the last month I have had a waxy feeling buildup on my hair at the crown. I have tried using the no-poo method (baking soda & apple cider vinegar), clarifying shampoos, dandruff shampoo, cleansing conditioner, gentle shampoos, all to no avail. I DID have some relief after soaking my hair in acv for half an hour before showering, but the waxy spot was back by the next day. Is this due to stress, hormones, or allergies, or can it be some kind of bacteria/fungus?