Self-doubt can be the destroyer of all good things. When you deal with a level of insecurity, your are limiting yourself to many possibilities of great opportunities. I know sometimes, it is hard to believe that you are capable of things that you think are unimaginable. Your reason for not going forward may be due to your fear of success, or your fear of failure. Maybe you cringe at the thought of rejection.
I can relate to a level of being fearful. I am in the process of starting my own business, and I can admit that I do let my mind get the best of me. What if they don't like me? What if they tell me my work is horrible? All of these thoughts go through my brain, when I am thinking about marketing my services. But you know what I say. " So what." If they don't like me , there is someone who will like me. And will be able to benefit from what I have to offer. I think the saying goes " It is better to have tried and failed, then to not have tried at all." Hopefully you get the point, but that is the saying that I try to live by. You never know until you try right? So be fearless in your ventures, and you will succeed even when you fail.