You cannot solve your narcissism through introspection. Introspection will only lead you to thinking you've found the answer, and stopping there so you don't have to change. "I've figured it out, I know why I'm a narcissist," and then stopping there.
People can't tell you how to stop being a narcissist. If someone tells you exactly what to do, you'll do that thing, and then stop. "I'm doing that thing now, so I'm not a narcissist!"
Your mind will simulate the most awful pain imaginable just to protect against changing your behaviour. You think your suffering is making you a good person, that by looking at the painful parts of your mind you are no longer a narcissist, but you're at the same place as you were before. You haven't changed your behaviour at all.
People can't tell you how to stop being a narcissist. If someone tells you exactly what to do, you'll do that thing, and then stop. "I'm doing that thing now, so I'm not a narcissist!"
Your mind will simulate the most awful pain imaginable just to protect against changing your behaviour. You think your suffering is making you a good person, that by looking at the painful parts of your mind you are no longer a narcissist, but you're at the same place as you were before. You haven't changed your behaviour at all.