This is a tough lesson to learn, but you don’t have necessarily have to prove yourself to others.
Growing up, you take tests and are always being graded. It creates this subconscious idea that you need to prove yourself. In some ways, it’s reasonable when you’re young to make sure you are developing and progressing appropriately.
However, as you get older and become more experienced, you’re less and less likely to be tested. You also know who you are and what your values are. Those become the new criteria to measure yourself. It becomes an internal metric.
If you keep at it and learn from your experiences, you’ll find those values. Unfortunately, it’s something you can’t learn solely from a book (although it may help).
People don’t talk about it, but as you get older there’s this shift from external validation to internal validation. Where instead of getting validated from others, validation comes from within.
It comes from knowing who you are, what’s important to you, knowing what you value, and then living in alignment with all of that.
Getting there takes time and experience unfortunately. The only way to expedite the process is introspection.