Why would it upset your ex-Narcissist to see you at NA meetings when he just dumped you for another girl?
Unless you have picked up some bad habits from him or have been
diagnosed as narcissistic then he's angry because he doesn't feel
you need to be at the NA meetings now that he is seeing someone
else. Narcissists don't recognize what and who they are and more
often than not counseling doesn't help them and of course his new
girlfriend would probably not know that he is .... yet! I have a
feeling you're doing it to get even with him. If so, stop! I know
you hurt and are ready to hang this guy, but he's not worth it! Get
on with your own life and kick this rat to the sewer.