This. You aren’t happy and you can’t make your boss happy. Accept that it was a mistake, “admit” that it was your fault for not understanding what they wanted,

This. You aren’t happy and you can’t make your boss happy. Accept that it was a mistake, “admit” that it was your fault for not understanding what they wanted, and go your separate ways. Don’t try to get a “dig” in on your way out, just leave on a good terms as you can.