Re: Are you self-handicapping? Probably not. You've got a real disadvantage. BUT that doesn't mean you should hold yourself to any lower of a standard. I find that a useful heuristic is to automatically answer "yes" to this question. In other words, if I told you authoritatively, "YES, YOU ARE SELF-HANDICAPPING - SNAP OUT OF IT" what would you do differently? Usually, whether it's true or not, those are the right decisions.
Re: Exceptional. I'm sure you are. Exceptional is a vague term and that can lead to big ego swings. We can all find evidence that we're "exceptional" and "non-exceptional" every day. The trick is to realize that assuming that your exceptional innate abilities will lead you to success without work is a myth. Just keep hustling. Excellence is a habit, not a trait.