"Take chances, make mistakes, and get messy."
As an artist this is just trusting the process, but lets put emphasis on make mistakes. Make mistakes. Make Mistakes. MAKE MISTAKES.
Every painting isn't going to be a Picasso, every poem isn't going to be a Komunyakaa, but every mistake will be a deeper exploration of self. A new way of viewing a problem. Insight.
Creatives have the amazing ability to make something from nothing, and that includes problems, stresses, anxieties, and doubts. Learn to view them as part of the process and incorporate them into your practice for more personally driven works. This creates within the work a sense of the individual, authoritative confidence, and pride to help combat those negative feelings.
Repetition is the key to all learning. If you want to paint a million beautiful pictures; you'll have to paint a million shitty or mediocre pictures in between. If you want to shoot like Kobe; first your jumper will look like Smush Parker's. Find peace in knowing the journey is constant and there's plenty more gorgeous mistakes to come. Just worry about getting your reps in.