These three often show up together in a muddled mass.
But they’re three fundamentally different things:
I don’t know what I’m doing (or what I’m supposed to do).
I’ll never know what I’m doing!
If what I’m doing doesn’t work, I’ll have two months to find a new way to make the rent.
Risk is arguably the easiest to manage: you can figure out your appetite and capacity for it with some back-of-the-envelope math or probabilistic thinking. (Should you leave 15 extra minutes to get to that important meeting?)
Fear and uncertainty, though, respond best to practice. The risk of falling at the climbing gym is pretty manageable, but that feeling in the pit of your stomach when you’re on the wall? The longer you learn to sit with it, the better you’ll be able to stand it.