I believe I got that and roughly beat it! It only took a few years!
Doing some rough carpentry, I dropped a 2 x 4 on my left big toe. No big pain. But later it appeared that I had cracked the nail. Later the nail began to crumble -- likely a fungus among us!
Eventually the nail crumbled its way nearly all the way back to the white part.
I got some anti-fungus cream, generic, big tubes, from Wal-Mart. So, I'd put a tablespoon of this cream on the nail, wrap up the toe with a piece of paper towel, secure it with whatever tape was handy, and f'get about it until after a shower, etc. and then repeat the procedure.
More than once the nail grew out again but was infected with the fungus. We're talking years here!
Finally I got lucky and the nail grew out apparently healthy.
Then there was another problem: The inside edge of the nail was a long way from growing out so grew against flesh giving me an ingrown toenail. Okay, been there; done that! So, slathered on some Wal-Mart generic triple anti-biotic cream, wrapped it up, and waited months until the end of the nail grew out past the flesh. Yes, the end of the nail was ugly with blood and dead flesh! Ah, soap and water! But there was no bacterial infection from the ingrown nail, and no fungus infection.
Now the nail is nicely grown out with little or no evidence of crumbling from a fungus infection.
So, I killed the fungus with just topical medicine and not some internal medicine that might damage my liver.
But, given the slow rate of nail growth, a case can take years!
The anti-biotic cream seems to be strong stuff: Once got some on my socks, washed my socks, and too soon saw sewage bubbling up in my backyard. Yup, the anti-biotic cream had sterilized my septic tank! So, flush a box of Rid-X or whatever, and the septic tank has been healthy ever since.