how long till milk production goes away?

Okay so I've pretty much went straight to formula with my 3 week old. Breast feeding just wasn't working for us. And yes I have tried everything and talked to multiple people/ doctors for help and nothing has helped. She just won't latch and screams with hunger becuase she doesn't want to latch and eat so I have to give her a bottle. But my question is how long till my milk goes away so I will stop leaking ?