Based on just this single story, my response may be overboard, so keep that in mind:

You should probably seek therapy. My wife's parents are narcissists. We all thought her younger brother (their GC) was also a narc for a really long time. Finally he had a falling out with them (he still lived at home and their house was turning into a hoarder house and they would get combative about it if he tried to clean, then got super pissed when he moved out - he was 25 or 26 years old when this happened). By virtue of the fact that he lived with nMIL and nFIL, my wife and her other siblings were NC with him as well. My SIL began talking to him again now that he was out of their house. He started realizing how abusive and terrible his parents really are, and how much like them he tended to act. SIL convinced him to seek therapy.

This was about five years ago. He seems normal to me now. Maybe a little over-the-top sometimes, but not someone who I just want to stay far away from me and my family anymore. Someone who's capable of admitting mistakes and actually apologizing and treating other people like actual human beings. But if you'd asked back then, I would've been 99% sure he's a narc just like his parents. Therapy helped him learn how to actually respect other people and boundaries and stuff - he did all that stuff because that's the behavior his parents modeled for him, not because he had a toxic personality disorder and just couldn't do empathy like a normal person.