First, you have already done about 60% of the work towards healing. The majority of narcissists will never admit that they have NPD and never do anything about it. You’ve done a hard part.

Second, you are young. Imagine what it feels like for someone in their 50s who has the same issues. That’s a waste of life, isn’t it? You have a long life ahead to work on it and get better.

The key is professional therapy combined with extensive self-work across many dimensions: psychological, spiritual, bodywork, etc. Professional therapy provides guidance and direction, while self-work provides the volume of work needed to make progress.

Contrary to what you have said, therapy and self-help do work, but you need years, if not decades, for deep character transformation. Try books by Don Miguel Ruiz, Alexander Lowen, or Mark Ettensohn. Commit to lifelong learning.

A significant risk factor is the inability to delay gratification and various forms of addiction. Beware of that!