Keeping a promise to yourself is how you start trusting yourself. Start with small ones.

Trust in yourself is not a feeling you talk your way into, it is a record you build. Every time you say you will do something and then do it, the record improves, and every quiet skip makes your own plans a little harder to believe. That is why large promises to yourself collapse so often, since there is no track record underneath them.

Make one promise this week small enough that failing would be ridiculous. Ten minutes, one page, one walk. Keep it seven times before you make a bigger one.