I appreciate what you wrote, OP - moderating my ambition is both essential to my mental health and an ongoing process. I do not exaggerate when I say that in my case I believe the stakes are life and death.

One thing that has helped me a lot to find peace here has been becoming a father. Culturally, it comes with a kind of license to finally just accept mediocrity which I find freeing. Bills are paid, I can watch my son grow up, doesn't matter than I'm not the best at anything.