I totally feel with you. As a matter of fact, I was thinking about that today, whether it's a fear of success or that of failure. Well of course, who wouldn't want to be successful? And the secret to success is maintaining at being successful, this is the difficult part So I cocluded, that it is because we are afraid to go forward with anything, we are actually confirming and making our fear of failure a tangible reality. Everyone has a fear of the unknown that is the future, so don't worry unless you start letting those thoughts of fear bring down your will to acheive...don't let that happen. Remember, your thoughts are transformed into actions, so keep them happy and positive.
As to my problem, that is similar to yours, I think the reason, though I prefer not blaming people on my own problems, is my father. He always put me down and made me indirectly feel that no matter what I do I will never be successful enough. So I don't know, maybe you had a family member that did the same to you as a child? If that, you should not let it affect you. You know you can do anything you want and you know deep down that not giving it your all will make you regretful later. Regret is not an easy feeling. So, what's there to lose? Think about it.
As to pursueing your dream as a preformer I highly recommend it, for dreams are always worth followed and acheived.
Good luck