You can't choose to believe something by saying it in the mirror; your brain knows when you're lying. Beliefs follow evidence you've collected yourself. So collect it: one small, real proof at a time (one talk, one sale, one rep you didn't think you had), and let the belief catch up.
P Evidence: promising. Good studies, but small or few. Use it and keep checking.
E Evidence: built from practice. What works for coaches and practitioners. Labelled that way.
Sources
People with low self-esteem who repeated "I'm a lovable person" felt worse than those who didn't; only people who already felt good got a small lift (Wood, Perunovic & Lee 2009, 2 experiments, 🟡) · "you don't choose your beliefs, you collect the evidence": Steven Bartlett (🟠) · see 275.
Not medical, legal or financial advice.