My doctor says I have narcissism, but I don't understand. What does it mean?

Narcissism is varied. Symptoms of narcissistic disturbances may include any of the following: low self-esteem, shame, grandiosity, sensitivity to criticism, insensitivity to others feelings, self-centeredness, pathological idealization and/or devaluation of others. Psychotherapy or psychoanalysis are the only treatments for narcissistic disturbances.
Narcissism. Means that you have low awl esteem and are particularly vulnerable to even small criticisms. This can make work and personal relationships very difficult for you.
Narcissism. The hallmark of a narcissist is an immense ego, grandiosity, and self-importance, as well as being entitled, and a tendency to use and objectify others as well as thinking of people in all-good or all-bad terms instead of shades of gray. The core of a narcissist is profound insecurity.