Narcissism

noun self-centeredness

• His constant bragging and self-centered behavior can be attributed to his egotism.
• She's always talking about herself, it's like she's the queen of egotism.
• That guy is so full of himself, total egotism on display.
• Egotism is like a wall that prevents you from truly connecting with others.

noun a feeling of pride and satisfaction in oneself; self-respect

• Excessive self-admiration can be detrimental to one's personal growth and relationships.
• She's always talking about herself, it's like she's full of self-admiration.
• He's so full of himself, always in self-admiration mode.
• In the mirror of self-admiration, one often fails to see the flaws that need improvement.

adjective describes someone who is excessively focused on themselves and their own needs, often to the detriment of others

• Her self-centered attitude made it difficult for her to form meaningful relationships.
• He's so self-centered, he never thinks about anyone else's feelings.
• She's such a self-centered brat, always putting herself first.
• His self-centeredness is like a black hole, sucking in all the attention and leaving nothing for anyone else.