At your worst, all you can do is your best.
Your best on a good day will be different than your best on a bad day. Take the pressure off of yourself by acknowledging that everyone has them and that it’s okay to adjust accordingly.
When you approach difficult days with the same expectations as good days, you set yourself up for disappointment and failure. You risk beating yourself up and feeling worse for not performing. Instead, focus on what is working in your life and remember that challenges will pass. Doing something creative or fun is a good start, and you can take it a step further by acting on what you know you can do well or by doing something that you know will make you feel better. Chances are your day will improve and your performance will too.