When you have slipped up, don't be critical of yourself. Nobody is perfect, so if you try for perfect, you set yourself up for failure. Don't try to make up the difference. Just jump back in where you are, and get back on track.
Treat yourself with kindness. Would you be this critical of anyone else? Don't worry about what happened. Thinking about those accomplishments you have already made instead of focusing on your mistakes will make it easier to get back on track!