DECIDE and DO it. Again and again and again. Make up your mind to do what you have to do in order to be who you want to be.
Your scale’s number on any given day has no bearing on the fact that your healthy behaviors must continue long term.
It is rarely what you do on one day or one week that makes a difference in weight loss. It is rather what you consistently do over time.
Don't chastise yourself into change. Let your inner coach have a voice that motivates, not undermines.