Preparation gives confidence something solid to remember.

Confidence needs material to work with. When you try to feel capable without anything to point to, you are asking your mind to believe a claim with no evidence, and it rarely cooperates for long. Preparation supplies the memories that self-assurance can rest on.

Keep some record of the work you have actually done, even informally, so it is available when doubt arrives. Before a hard moment, read it rather than reciting affirmations. Belief that comes from remembering is much harder to talk yourself out of.