Actors: We Are Our Product.
In most jobs, the goal is to sell a product. As actors, we are what we're trying to sell. Essentially, we are our product. Therefore, when we don’t book something it’s easy to jump right to “Well, I’m not good enough”. Get that thought out of your head, because that’s not true in the slightest. When you don’t get cast, it’s not because you, yourself, are not good enough. It’s that your product isn’t right for this particular role/show. That doesn’t mean it will never be right for this particular role/show and it also doesn’t mean that you, as a human, are not good enough. I know for a fact I’ll never play Christine Daaé, because my product just isn’t right for that job, but that doesn’t mean I’ll never play Eponine. We can’t get every job; no person is so well rounded that they can play every role ever. Except maybe Meryl Streep, BUT WE AREN’T MERYL STREEP. So, let’s not try to be. Focus on being the best YOU that you can be. Work hard and make your product what you want it to be.