A good plan has a stopping point. Decide when you’ll quit before you start.

Without a stopping point, the only way out of something is for it to get bad enough, and by then you have usually put in far more than you intended. Deciding beforehand means the decision gets made by the version of you who can still see clearly. In the middle, every further hour feels justified by the hours already spent.

Set the limit when you start: this many attempts, this much money, until Thursday. Write it where you will see it. Hitting the limit does not force you to stop, but it does force you to choose again on purpose instead of drifting.