It's so easy to look at others who have "succeeded" in their careers or their creative work, and compare ourselves and feel like we're not good enough in comparison. But hindsight is 20/20. Look at how each of your hero's choices brought them closer to their goal. Where they are today shows how obvious and clear their path was. And yet, at the start (unless your hero is Arnold Schwarzenegger) they had no idea where their path would take them.
I like to look at Woody Allen, for example. I love the trajectory of his career. He began writing for television, then did standup comedy for a few years, then he began writing, directing, and acting in his own films. He's in his 70's, and he's still making a new film every year. But I don't compare myself to him anymore, because I've realized I want to carve out my own path. Each of us, especially people whose creativity is at the center of their lives, makes a beautiful and unique meandering toward our deepest truth. And we do it without knowing if or when or how it will "all come together". This reminds me how we're part of the great mystery of life!
I'd like to propose that the people you admire were not actually aiming for Success or Getting Things Right or Looking Good so much as really being curious about and exploring themselves and the world around them. They were becoming themselves, and the opportunities that arose came out of a willingness to take the risk of really knowing who they are. And things "all come together" at exactly the moment when you decide you're ready for it, and when you decide you really really want it.
So, take a moment, look around, and recognize that you have chosen (consciously or unconsciously at a deep, soul level) exactly who and where you are in order to learn something at Earth School. And relax into the knowledge that you are exactly where you need to be on your very own path. And then, make some new choices. Take some new risks. Make some new mistakes!
"The Path that leadeth on is lighted by one fire-the light of daring burning in the heart. The more one dares, the more he shall obtain."
-Helena Petrova Blavatsky