Here's how to stop feeling guilty:

• Stop magnifying: Ask yourself if your self-punishment fits the crime. It probably doesn't.
• You are not your actions: You're responsible for your actions but they don't make you a bad person. Remember USA.
• Self-compassion: Forgiving yourself makes you behave better. Thinking you're a bad person makes you act worse.
• Apologize: Say you're sorry for what they think you did wrong, not what you think you did wrong.
• Ask "What can I learn from this?": Torturing yourself doesn't make you a better person. Learning does.

You'll screw up again. It will happen. But you don't have to be tortured by guilt again. In his book, Burns explains the best attitude to take:

Learn to accept your limits and you'll become a happier person.

Forgive yourself. Repair the damage. And move on.

You're not a bad person. But you sometimes do bad things. You know what that makes you?

Human.