"Fears are nothing more than a state of mind."
-- Napoleon Hill
Although you may have measured your abilities on what you can and can't do, it is not still impossible to achieve higher aspirations. Set yourself away from fear and start performing -- doing other things. Work until you surpass your old self. By then you will know that you are more than what you thought you are or what other people are saying who you are. And you know you can push further. Further.