Narcissists will never voluntarily do therapy. The brain is a simple organ. It only learns new things by being surprised, when something unexpected happens. This has to be repeated over and over again to have an effect.

I'd recommend you take a look at schema therapy and mention it because I recognise the emotional state that comes across in what you post. Schema therapy would talk about this as "angry child mode". Which is not intended to invalidate the very real reasons you have to be angry. It becomes a prison, isolation yourself from different parts that exist within you that could otherwise work in your favour to help you achieve what you want or better advocate for your needs.

Without the support of someone who knows what they're doing that angry child mode is a never-ending pit of despair and source of guilt.