Failure is enriching. It's also important to accept that you'll make mistakes - it's how you build your expertise. The trick is to learn a positive lesson from all of life's negative moments.
For me personally, I have a fear of, 'If I stop, I'm going to die.' If I stop doing the things that are enriching to me or creatively exciting to me or if I stop creating, then I feel stagnant. If something isn't growing, it's dying.