Projection is a defense mechanism where someone denies their faults and attributes them to others. They accuse you of doing things that they themselves are doing.
It often involves blame-shifting and shaming.
When someone projects, blame-shifts, or shames you, there is a temptation to explain yourself, defend yourself, or prove your point. If you get caught in this trap, you are wasting your precious time and energy.
Instead of defending yourself against a false accusation, the best thing is to not engage and walk away and end the toxic relationship if the person is unwilling to change.