It's not enough to know that the only person you can change is yourself, because even when you stop trying to change other people, you don't stop hoping for them to change on their own. An epiphany, a life crisis, a spontaneous conversion. You may not be able to force the transformation, but perhaps you can wish it into existence, or leave clues leading to it, or nudge the process along.
One day, if you're fortunate, you may have an epiphany of your own: that the change is not coming, or at least is so infinitely unlikely that you would be better off going forward with the assumption that the dreamed-of shift will never come, rather than standing still, sheltering the flickering light of your delusional hope.
This is not to say that all hope is delusional, only that the best place to invest it is in yourself, as the agent of change in your own life.
Your hope lies in understanding your past, accepting the present, and believing in your ability to build a new future.
You are the adult child of a narcissist. So am I.