Feeling bad about a mistake is fine for a night. After that, it’s just a way to avoid fixing it.

A night of feeling awful is a normal response and sometimes a useful one, because it marks that something mattered. Past that, the feeling starts doing a different job: it occupies the place where action would go, and it looks enough like responsibility that nobody asks what you have actually done. Guilt is quieter than repair and much easier.

Give yourself the night properly, then write down the single next action in the morning. One thing, with a time attached. The feeling tends to lift on its own once something real is underway.