At one end of the self-loving spectrum is the charismatic leader with an excess of charm, whose only vice may be his or her inflated amour-propre. At the far end of the spectrum reside individuals with narcissistic personality disorder. 
From Psychology Today
Narcissistic personality disorder is a mental disorder in which people have an inflated sense of their own importance, a deep need for admiration and a lack of empathy for others. But behind this mask of ultraconfidence lies a fragile self-esteem that's vulnerable to the slightest criticism. 
From Mayo Clinic
Narcissism means a man or boy being absorbed with himself and imagining how wonderful he is.
Narcissism means a woman or girl being absorbed with herself and imagining how wonderful she is.