Self-confidence comes from thoughts or actions?

I’m so excited for the June self-confidence work! I just read through the materials at the beginning of the workbook. I’m perplexed as to whether self-confidence, as Brooke defines it, comes from our thoughts or our actions. I know the “right” answer is that it comes from our thoughts. But on page 5 at the bottom of the page, it says “The ability to trust yourself comes from consistent follow through on your word to yourself as a starting point. You aren’t born with self-confidence: you earn it for yourself by keeping your word and doing what you say at the highest level.” Similarly, on p. 12 it says “Actions increase capability, and capability increases confidence.” Should I understand that to mean that the neutral circumstance is the past history of keeping your word, which then leads to thoughts about trusting yourself, which then causes the feeling of self-confidence? That seems like it is ultimately relying on evidence to get to the feeling of self-confidence. And then my brain goes to my history which I think is riddled with evidence of not keeping my word to myself (yes, I realize this is a thought, though it also feels “true”), which leads me to feeling self-doubt. What am I missing? Thank you!