Since you can't go back in time and correct your mistake, the next best thing to do is to ensure the next time you are in a similar situation you are aware of it and you are strong enough to handle it with aplomb. If not, then stay away and train and build strength.
Keeping promises is hard. It requires us to do things we don't want to do. But keep those promises you must do. Otherwise, do not make them in the first place. But since you have made them, you must keep them, especially if it would benefit all those involved including yourself.