I feel like this idea of wanting to do something well (near world-class) is so entrenched in my mind that it feels like not striving for something big goes against my very identity.
The sooner you abandon this unhelpful mindset, the better.
Somewhere in your upbringing, you've been taught some combination of the following:
1. You are what you do
2. You are loved or valued when you produce
3. You don't exist when you are anything other than the best
You now know that this messaging is damaging to your taking concrete action and sense of well-being.
Excellence is a worthy goal, but not absent a larger purpose that informs and defines *why* you are striving. Humans live best as vectors, not scalars.
Values sorting
https://www.thegoodproject.org/value-sortStrengths inventory / ranking
https://www.viacharacter.org/character-strengths