If you lack self-trust, your brain acts like a filter that only lets in your mistakes and completely blocks your successes. You can remember a embarrassing thing you said in 2018, but you completely forget that you handled a massive crisis at work last Tuesday.
To change this, you have to actively practice internalizing positive feedback—both from others and from your own self-reflection. Start tracking your "proof of capability." Write down when you handled a hard conversation well, when you showed up for a friend, or when you made a smart choice. Give yourself credit so your brain can see the data.