How are you managing your split nails?

Even though I have a washing machine, there are many things to wash by hand, and my job involves a lot of handwork, so

My hands aren't being taken care of properly.

Is my fingernail peeling in double layers due to a protein deficiency?

Should I take nutritional supplements?

Or should I apply it to my fingernails?

Which one would be better?

How are you managing this?