I'm feeling a bit down and out of my depth

None of the incredibly successful startup founders I know have substantially failed at anything in their career. They bounced through school with perfect grades, went to a world famous institution, and were successful at starting up on their first try.

I very nearly failed my A-levels (UK end of highschool exam) and went to an average university.

I built over the first year a grocery delivery marketplace, and dropped out to go full-time. It imploded 3 months later.

I got rejected from a prestigious accelerator after that.

I got a job at a YC company, and was laid off 8 months later for not matching the founder's vision.

I reapplied to the same accelerator and was accepted and got a co-founder, and applied to the Thiel Fellowship. Rejected after 1 interview.

People always tell us when we're growing up that you need to fail in order to succeed but I don't think that's true. A very small amount of failure might help with the experience, but truthfully, repeated rejection lowers odds of success. When talking with other founders I feel weak compared to people who've been good at everything they've tried.

Common woes, but they've left me feeling down. Any advice for overcoming the negative emotions?