It is in the moment that the mind chatter justifies the option that requires less discipline, that is when one must exercise their discipline the most. A mind that chatters less, is a mind that has been beaten with a habit such as this, it is when we teach the monkey brain just as we would a small toddler, through pleasure and pain. Where justifying the easy way out (while being less strategic to end goals) results in the pain of doing the way that requires a better movement of discipline and will, here is how you whip it into quietening and holding itself to only speak when spoken to. The rampant inner dialogue is something that is allowed by the observer, it can be changed at any time, if or when only one develops the spine to do so. For which you already have.

Meditate.