Not exclusive to narcissism or even self help but I loved Tiny Beautiful Things by Cheryl Strayed
This website helped too:
https://outofthefog.website/
Dr. Ramani on YouTube is also amazing:
https://m.youtube.com/channel/UC9Qixc77KhCo88E5muxUjmA
Love this column too:
https://therumpus.net/2012/05/dear-sugar-the-rumpus-advice-column-98-monsters-and-ghosts/