YES. You can overcome your Nmom as trigger. Immunization from the N has little to do with the N itself and everything to do with your understanding of yourself.
This is the key: As long as you need or expect something - anything - from the N, you are vulnerable and you will be triggered. You must be 100% psychologically independent from the N such that when the N says something nice it has the exact same effect on you as when the N says something insane or nasty.
You can only control your own mind, not the N or the N's actions which will never change. You cannot trust yourself until you have looked into it very carefully via fearless and determined self-observation.
Like all of us, you have been conditioned to respond to certain triggers. This unavoidable and happens to us all. When the conditioning we receive from parents, school, life, etc. is positive it leads to good feelings and when it is terribly terribly bad, it leads to terrible feelings like those you are now experiencing.
You must journey inwards and locate the subroutine or piece of conditioning that makes you vulnerable to triggers emitted by your N. You must drag that little piece of aberrant programing out of your memory and into the light of day where you can examine it scrupulously, dissect it and fully apprehend it.
Usually, that's all it takes. Clear observation of the problem solves the problem.
Part of the process involves learning how to surrender to that which you cannot control. This is exactly what junkies need to learn from AA: the serenity to accept the things we cannot change.
You must accept, 100%, without reservation that your N will never love you as you want to be loved, will never respect you as you deserve to be respected and will never be able to give you what you want from her.
As soon as you no longer harbor any expectations whatsoever, you will be free. Your N will be disarmed. You will be totally prepared to deal with whatever they spew forth without an emotional response. This is a wonderful thing and it took me 50 years to comprehend and only a few minutes to implement once understood.
My mother is not an N but a psychopath - a closely related empathy-deficit disorder that is absolutely intractable. It cannot be altered or tempered or discarded. They will never be capable of love, respect, sympathy, support, affection, honesty, selflessness and on and on.....
The wonderful part is that as soon as I finally understood my mother and myself and was free of all false hopes, I started being able to enjoy her company in small doses without fear. She did not change, but I did. I no longer need anything from her. Nothing. So I can interact with her and enjoy her originality, indomitability, energy, lack of remorse and other NPD or PPD traits.
This is what you must do. Then you will be truly free and you will never be confused, heartbroken, guilty, inappropriately remorseful in the misguided and totally false idea that you are capable of hurting the N and must feel guilty if you flee to protect yourself.
One other benefit for us older offspring of Ns is that we never have to worry about the devastation of loss. We never had whatever it is people fear to lose when their parent passes on.
I never worry if I haven't called my mother in several months. She hasn't been worried or offended or hurt. She's indifferent. I don't have to lie to her because it doesn't matter what she says about it. I am the same before and after. It's amazing. If someone had told me this was possible 20, 30, 40 years ago, I would've thought they had no idea what they were talking about. But I've done it. It works 100%. Stay free OP. The freedom I'm talking about is the freedom from your own conditioning. Freeing ourselves from conditioned responses is something every one of us must do if we are to live a happy life without lugging around heavy baggage from our tortured pasts.