It goes back to the old scuba agency recommendation - dive within your comfort zones. If you fear narcosis, then avoid deep dives. Simple as that.
Narcosis itself can be a subtle and insidious debilitator. It can present in a multitude of ways, dependant on the individual, the individual's mood and other factors. It is rarely obviously evident to the individual themsevles and, very rarely, a sensation akin to the typical 'drunkeness' analogy that some divers/instructors use to describe it.
Most divers would not have a problem with narcosis above 30m. Those that do, are typically experiencing mild narcosis amplifying a pre-existing mental state (apprehension, enjoyment etc).
Controlled exposure to narcosis has argueable benefits. The AOW deep dive may allow some experience with narcosis (it doesn't for most divers), but at least you are supervised and safe during that time.
If you fear narcosis, then there is a chance that any mild narcosis could present as an amplification of that anxiety. A stress-related narcosis experience can be very unpleasant and can lead to an out-of-control panic reaction. If you are fearful on a deeper dive, then you should certainly ensure that you are supevised/protected by a competant and experienced buddy (and that you communicate those fears in advance of the dive).
The question remains, whether an experience of narcosis would serve to alleviate your fears or increase them. Likewise, postponing that experience could possible also serve to exagerate those fears (because the reality will remain unknown), when actually, doing the AOW deep dive may put your mind to rest.
Personally, I am inclinded to confront my fears. Having said that, I also wouldn't allow a negative experience to deter me from further diving.
With that in mind, the first step for the OP would be to analyise themselves to determine how they may react to a negative narcosis experience - and balance that against the possible benefits of gaining that experience.