'to spite'

"Cutting off the nose to spite the face" is an expression used to describe a needlessly self-destructive over-reaction to a problem: "Don't cut off your nose to spite your face" is a warning against pursuing revenge in a way that would damage oneself more than the object of one's anger.

It means that you do something in anger that will only hurt you

The saying "don't cut off your nose to spite your face" dates back to the 12th century. It originated from a story about a man who, in a fit of anger, cut off his nose to spite his own face. The phrase is used to caution against taking self-destructive actions out of spite or revenge.

Think about cutting off your nose - it would hurt like heck and be really ugly and you couldn't breathe well afterwards. This idiom refers to doing something that ends up being worse for you than it was for the person you were trying to punish by doing it.