Natural Remedies for Scalp Infections

About one month ago I started getting these small barnacles ( for lack of a better word ) I used a Rx shampoo

And I thought all was well UNTIL

I started getting these raised sores and stabbed areas.I went to dermatologist who then gave me Clindamycin and a gel - oily steroid to put on the open areas. That all went away ..BUT then comes these massive amts of sandy, grainy junk all over my scalp. I wash and soak it with OTC shampoos to know avail. I can pick off the mounds of sand but within a minute it seems there it is again. I am currently taking doxicyline for a month. I have tried a mixture of half n half organic ACV with water. Again no help. So does anyone have any ideas.?

Thank you for reading.