You have my sympathy. As a mycologist, I was reluctant to treat myself with a systemic fungicide, and thought I was clever enough to find some alternative. That was 15 years ago, and none of the over-the-counter remedies have worked. I surface-sterilize plant tissues with 10% bleach or 70% ethanol, but neither of those will penetrate keratin. Someone suggested neem oil, which I thought might penetrate the nail, and it does work a little, but after months of twice-daily applications, I gave up on it. The only thing that worked at all was me breaking my leg and having to elevate my foot for 6 weeks. Why do you think that was? Better blood flow? Higher temperature to my extremity since it was in a cast? I have no idea. I don't suggest that you break your leg.