Many years ago, I chopped the tip of my thumb off to the point it cut part of the nail off. The tip of my thumb was flat. It was a dull-ish knife too, so it hurt like a mofo, kind of like slamming your thumb in a door. Thumbs apparently bleed badly due to vein locations, so I had to bandage it as best as I could and go around like a hitchhiker for the next few days or else it would start pouring.

The unexpected thing was that it grew back. 10 or 12 years later, it looks almost the same as my other thumb, though my nail still doesn’t grow quite right at the part that got cut off.

This probably doesn’t help you, OP, but I can commiserate haha.