One of my more embarrassing struggles of young adulthood was my struggle with seborrheic dermatitis. (Although I didn't know that's what it was at the time, and frankly, I don't see a reason why anyone should be embarrassed by that.) All I knew was that my head was very itchy and extremely flaky. It was rather gross, and I figured I had to be doing something wrong with my hygiene. I had to have not been washing my hair often enough, right? Or…maybe I was washing it too often? I assumed it was caused by a dry scalp, but wasn't sure how to fix it.
Finally, I was at the doctor for my decennial checkup I mentioned it to him. To my surprise, he didn't think it was dry skin at all but instead sword dermatitis. He prescribed me a 2.5% selenium sulfide "shampoo" and said to see if that cleared it up.
I had actually tried similar over-the-counter dandruff shampoos, and they didn't do anything. However, he told me these had special instructions, so I made sure to read the bottle before using it.
For treatment of dandruff and seborrheic dermatitis of the scalp:
Massage about 1 or 2 teaspoonsful of suspension into wet scalp.
Allow to remain on scalp for 2 to 3 minutes.
Rinse scalp thoroughly.
Repeat application and rinse thoroughly.
After treatment, wash hands well.
Repeat treatments as directed by physician.
Apply to scalp, rub in, and what? Let it sit for 2–3 minutes? Then do it again? I had certainly never intentionally done that with shampoo before. As soon as I felt it was lathered, I would wash it out. However, this means that none of the shampoos I tried were really doing anything. If they couldn't sit on the scalp then they wouldn't be in contact with the fungus long enough to kill it. No wonder nothing had worked before.
I tried applying this stuff according to its directions, and I saw instant results. My doctor had told me to do it twice a week for as long as several months if needed, but I didn't even do it that often, and it worked wonders for me after the first couple times. I no longer had any flakiness, and essentially no itching. My trichological life was radically transformed. It's a wonder what actually listening to medical experts can do, eh?
If you are in a similar boat, I would encourage you to similarly reach out to your doctor for help, and if you are trying OTC products and not seeing results, I would definitely try actually following the instructions and letting it sit for a while. While you can't buy 2.5% selenium sulfide products over the counter, you can buy 1% selenium sulfide shampoo, which hopefully might do the trick for a very small price. If nothing else, at least take away that this problem is fixable and not your fault.
Note: I am not a medical doctor. You should be getting your medical advice from your licensed physician, not some random person on the internet.