Listen to how you speak to yourself when something goes wrong. The tone. The speed. The certainty. For most of us it doesn't sound like a friend. It sounds like an old teacher, an old parent, an old fear.
That voice was not born with you. It was learned — usually at a time when being hard on yourself felt like the only way to stay safe, loved, or in control. It made sense once. It just doesn't fit anymore.
You don't have to fight the inner critic. You only have to notice it, and then choose another voice: the one that would speak to a friend in your exact situation. That voice is also yours. It's just quieter, and it needs practice to speak up.