No matter where you are in your career, looking for a new job is an incredibly stressful time. It's common to experience feelings of inadequacy, rejection, and general imposter syndrome.
This is a natural consequence of company hiring practices, which typically are engineered to minimize the rate of false positives (e.g. hiring someone unqualified for the job). Knowing this doesn't always ease the pain of not landing that dream job, though.
Even so, it can be helpful to try to zoom out and take a high level, objective look at the job search process. That's what I'd like to do here. My hope that by exploring a model of the job search, you'll be able to more effectively budget your time and more quickly find success.