First and most important learn to be sincerely grateful for this experience to yourself and the others that make it possible.
This is difficult for at least 2 reasons. First, many (most?) are familiar with gratitude only as a concept but not that much as a feeling. Second, your attention is focused on frustration caused by your awareness of your narcissism as it makes you suffer.
In order to get that genuine feeling of gratitude the focus on your suffering must be dismissed first. Once you caught yourself in this state, notice what your body feels. Pay attention to your eyes, tongue and throat. Relax these while exhaling. You may notice that slight tension behind your forehead caused by keeping focused goes away. Now you're unfocused.
Next, it is necessary to train yourself to be grateful in such situations. As you're suffering from narcissism that is a form of attachment, sort of greed in other words, which naturally blocks gratitude, this will most likely require some effort. Finding your personal trigger for that may be a good way. For instance, some situation in the past where you were truly grateful to someone or something. Once you find that you got the antidote.
This way you may learn that your narcissism isn't something that needs to be fixed but rather your way to learn something about the world and yourself. And maybe it's not even narcissism anymore? It just needs some gratitude. And maybe someday it will be exhausted as there's nothing more to learn, but that won't matter anymore. I personally haven't gone that far yet with mine :)
This is difficult for at least 2 reasons. First, many (most?) are familiar with gratitude only as a concept but not that much as a feeling. Second, your attention is focused on frustration caused by your awareness of your narcissism as it makes you suffer.
In order to get that genuine feeling of gratitude the focus on your suffering must be dismissed first. Once you caught yourself in this state, notice what your body feels. Pay attention to your eyes, tongue and throat. Relax these while exhaling. You may notice that slight tension behind your forehead caused by keeping focused goes away. Now you're unfocused.
Next, it is necessary to train yourself to be grateful in such situations. As you're suffering from narcissism that is a form of attachment, sort of greed in other words, which naturally blocks gratitude, this will most likely require some effort. Finding your personal trigger for that may be a good way. For instance, some situation in the past where you were truly grateful to someone or something. Once you find that you got the antidote.
This way you may learn that your narcissism isn't something that needs to be fixed but rather your way to learn something about the world and yourself. And maybe it's not even narcissism anymore? It just needs some gratitude. And maybe someday it will be exhausted as there's nothing more to learn, but that won't matter anymore. I personally haven't gone that far yet with mine :)