If you want to improve, in anything, eventually you will need to let you of the fear between steps of growth. Let go of your ego in the sense that you stop caring if you fail, and what people will think of it, because the fear is often based on that. But failing is necessary for growth, that's how you learn and improve over time.
So; accept the challenge, teach your mind to make it's automatic response be excitement instead of nervousness of opportunities of growth (a.k.a. practice).
This came out of a conversation with @FreshMan5000, and he also said (and I'm paraphrasing):"I made up my mind to tame my ego, to make a deal and say: "Okay, you can go crazy and want to achieve or create the maddest things, and I'll fuel my creativity with it and step onto new levels with courage, without doubt and open minded."
Beware that what you have in mind is amazing. On the one hand you might not be able to achieve that exactly, but if you're open minded and let your ego make some crazy moves, you might just achieve something just as great or greater, just in a different way.
So let your ego think you're freaking amazing (because you are) and translate that into productive creativity.
Don't let it make go big-headed, let it help you achieve great things without fear.
How does this resonate with you?