Welcome to WS!
I don't know if you'll check back here but...for you & others with similar questions, you might like to do a search for narcissistic personality disorder. (NPD)
A good place to start (once you google it) might be the DSM or even mayoclinic.com. You can also just wikipedia it.
People with Narcissisitc Personality Disorder (NPD) have extremely low self esteem.
I've snipped this from mayoclinic.com, which is layman-friendly:
Happy Sleuthing!
Thank you for the warm welcome, Emma. Hope this doesn't come across the wrong way but my undergrad degree was in psych and masters degree was in a counseling-related field. I do know what the "psychological" literature says about narcissism and self-esteem and I just don't buy it. Psycho-Babble aside, Casey clearly loves Casey and no one else - her behaviour screams it out. I know traditional psychology says that if one's self-esteem is low they really can't love anyone either. And I do believe Casey has not demonstrated regard for anyone other than herSELF. But that is just my point: Isn't what we believe to be low self-esteem in reality having regard ONLY for oneself (i.e., self-absorbption?) No one demonstrates this for me more clearly than Casey and what I have observed of her behavior. But of course, this is just IMO. Gosh, hope I didn't offend anyone (especially as a Newbie here