Finish the sentence “I’m someone who...” with an action, not a feeling. Then go do that action once today.

Self-descriptions built on feelings cannot be checked or acted on, so they float. Built on actions, they become testable, and the test is available immediately, since either you did the thing today or you did not. That is uncomfortable, and it is the only version you can build anything on. Identity follows behaviour far more reliably than behaviour follows identity.

Write your sentence with a verb in it. Then do that verb once today, however small the version. One instance is enough to make the sentence honest, and honest sentences tend to repeat.