You are very brave, Chris, to discover this about yourself and want to examine it, and want to change. The fact that you discuss it here, amongst "strangers", indicates you are sincere... because what motivation would you have to post if you did not really believe this about yourself? Here, there is no one that you wish to manipulate or victimize. This will heed the possibility of change for you.
I recommend visiting the other forum on this website, "things that have helped" or some such title. You will find invaluable resources there for a start - books, websites, and others.
Chances are that if you are truly a narcissist, you have come from a narcissistic parent. Therefore, I think you might already be in the right place. I think perhaps the place to start is to explore that possibility, and do some healing and acknowledgement in the area of your family origin. And, they may not have been narcissistic, but dysfunctional in another way that caused you to defend yourself with narcissistic behavior. In any case, you will not be able to "heal", or acknowledge your true self, if you do not do this first.
Many of us here have many narcissistic traits, and most of us came from narcisstic parents. I know I can speak for myself that I have been working on changing my own narcissistic traits as I heal from my Nmother's inflictions and abuse at the same time.
Be gentle with yourself. Discovering this can be very eye opening and painful, because you begin to realize how you've hurt others (I have). Some people here may argue that you can never change, but I disagree. It depends on your degree of narcissism, and how much you are willing to do to change. Acknowledgement is the first step. Good luck in your quest.