When I decided to start my own business I was excited, nervous, scared, and a bunch of other emotions. I would tell myself over and over it was ok to be scared, and nervous. It is OK to feel those emotions. Starting a new business is very stressful as well as very exhilarating. Many different thoughts pop in, but so do different opinions. Since my game has a story I'm writing I bounce ideas off of people and sometimes they're picked apart which can be a blow to the ego.
Considering this it was important that I keep a confident frame of mind. Some people believe confidence is bad. They confuse it with arrogance. I almost always believe I am the best choice all things being equal. I think anyone should feel that way.
However, I realized I was putting way too many negative thoughts into my mind and that led to alot more anxiety than was necessary. My self-esteem was a bit damaged. So what I've done is use more positive, if not pro-active thoughts. I just think how excited and motivated I am. That I will start my business. I also tell myself I'm ready, and that I've waited my entire life for it. This has helped me stay positive which has kept me focused on the task.
Little shifts in thought over time can make a big difference.