I'm a huge fan of Mark Manson, a writer I really admire. He's kind of a generalist who writes about all sorts of things. Here are some of his thoughts on confidence, which you should read in their entirety:
No, the solution to the confidence conundrum is not to feel as though you lack nothing and delude yourself into believing you already possess everything you could ever dream. The solution is to simply become comfortable with what you potentially lack.
people I admire
Bret Easton Ellis