For natural nails, get a glass file. The abrasive surface is etched into the glass rather than glued on, so it leaves a smooth, sealed edge when you file. Mine is years old and still works like new, and you can rinse it clean.
Daily filing is where glass helps. Emery boards leave the edge frayed, which is probably why yours are tearing (see this one). File in one direction, not back and forth like a saw, and the edge stays smooth.
Since you play guitar, get a small one for your gig bag. Brand doesn’t matter much, make sure it’s real tempered glass and not glass-look plastic. The Czech-made ones have a good reputation and aren’t expensive.