Worrying sucks. It takes us away from the present and makes us unhappy. It makes us overthink and assume the worst. Worrying itself doesn't solve problems. It can instigate actions or change future behaviors that can. So why not just focus on the action and behaviors, and skip the worrying?
Catch yourself worrying and examine why. Write down your worries and follow ups to get them out of your mind. Only care about a few important things and be carefree about everything else. Remind yourself you can't change the past or anything that you don't have control over. Tell yourself that you are human, you aren't perfect and you make mistakes. You can only learn, grow and do better next time. Be more thoughtful about the things you do, stick to your principles and promises so that you have to worry and regret less about them.
Worry less, grow more.