I've noted something before, and I want to repeat it every so often. Years ago, I began reflecting on my reactions to things, and I concluded that fear is stupid. It doesn't make you more prepared for success, and anyone that is successful must learn to block out their fear or face the paralysis that it will create.
START by recognizing that you are not perfect, and no one else is perfect, either. Then, recognize that if you make mistakes, you are human. Everyone that makes mistakes on this planet (which is everyone) is going give you some breaks. When I was in the military, they prized someone that was WRONG but led their troops with confidence on the wrong information over someone that was always waiting for the perfect time or perfect conditions. Winston Churchill said, "The Maxim, Nothing but perfection, may be spelled paralysis."
Will you mess up? Sure. So will others. But, if you approach things with fear, you are ALREADY messing up by not allowing yourself the grace to enjoy what you are doing, choosing instead to dread the potential that you might fail and therefore make everything a land mine.
So.. go make mistakes, and enjoy the journey, as you do. You will learn the same lessons others learned, but you will have a better time as you do.