I think you raise a very valuable point here. “Narcissist” is so often used simply as a label for the villain with no consideration for the terms use as a medical diagnosis.
In your case, you may be labeled a narcissist but you make a continual conscious effort to account for the weaknesses implicit in that diagnosis. This is different from the vitriolic insult so often used to condemn people.
This is a failure on our part, in the way we use the term. You may be (technically) a narcissist, but, you are not “evil” in the way that others popularly labeled “narcissists” are. You are a good person.
OP: “god, it’s hard being a paraplegic and trying to run…”
You: “guys, don’t listen to this asshole, being a paraplegic means you can’t run. If this person were actually NPD, it would be an extremely positive sign for them to seek to improve themselves and since we can see this person trying to improve themselves, they are clearly lying and manipulative. Classic NPD.”
Log off and touch grass. You can come back when the stench of your self righteous diarrhea of the mouth fades.