It's called, Self-Cannibalism. It's a disease.
A person who has a lot to say about themselves can be called self-absorbed or narcissistic.
Someone who is obsessed with themselves is commonly referred to as narcissistic or self-absorbed.
A self - eater, i think.
a loner
self-centered, selfish, egocentric
Self Flagellation
The term for someone who constantly blames themselves for everything is "self-blaming" or they may exhibit traits of "self-blame." It can also be a symptom of low self-esteem or excessive self-criticism.
Self-concept is how someone views themselves, while perception is how someone interprets their surroundings. Self-concept can influence perception by shaping how someone sees and interprets the world around them. Perception, in turn, can also affect self-concept by influencing how someone feels about themselves based on how they are perceived by others.
People who talk to themselves are often referred to as "self-talkers" or "soliloquizers." Additionally, if someone talks to themselves as a way to cope with situations or to better understand their thoughts, they may be described as "self-talkers" or "self-reflective."
When a person intentionally kills themselves, it is called suicide.
The opposite word for self-effacing is "boastful" or "self-aggrandizing." This refers to someone who promotes themselves excessively and without humility.