It's funny how people make important decisions in life, the most important decisions of their life, based on what everyone else, the unimportant outsiders primarily, will think about things. Pretty backward way to live.
Stop asking yourself what if you can't do it, and instead as yourself what if you can? What if you can write a bestselling novel? What if you can accomplish your dream to be a published writer? If you're willing to work for it, you can.