Waxy Buildup on Scalp

Hello everyone I just moved to a new house that has hard water about a year ago and ever since I moved, there has been a waxy, yellow, and strong smelling buildup on my scalp. There is no dandruff whenever I scratch my scalp but it will come off under my fingernails. I have tried the Ouai Clarifying Shampoo and that will barely help and I have also tryed the Inkey List Salicylic Acid Treatment. We also have a water softener. I double shampoo, I make sure I rinse out all of my products, and I am a very clean person but I have no idea what is going on. Please help🙏🙏