Second 18:32. Also, you don't mention if the "narcissistic" diagnosis is official or not, but, regardless, these disorders typically co-occur with traits of others. So, really, what you need is not necessarily a specialist in narcissists, but a very experienced, highly-recommended therapist listed in your insurance network.
Best thing to do is just review your insurance network list of providers alongside a reputable "best" list of providers. For instance, Washingtonian provides an online list of best psychiatrists. You need a psychologist, but a "best" psychiatrist might be a good way to start - at least the psychiatrist would provide you with several recommendations of psychologists.