Watch how you speak to yourself the moment you slip — the missed goal, the mistake, the thing you said you wouldn't do and did. For many of us it's a voice we'd never use on anyone we loved.
We're told the harshness keeps us sharp. It doesn't. Shame makes you want to hide, and hiding is where one slip becomes a spiral. Nobody ever beat themselves into lasting change; they only beat themselves into quitting quietly.
Speak to yourself the way you'd speak to a friend who stumbled — honest about the miss, but on your own side. That isn't softness. It's what actually helps you start again.