The saga of the cowardly egoist

It's rare to find a story in which the main character would be so selfish and cowardly at the same time. We can say that his character is depicted quite realistically.. there is nothing good about him, he is a coward, does not know how to communicate, he is weak, and at the same time he tried to monopolize his childhood friend, who is his girlfriend, when she turned from an uncut diamond into a real diamond. At times when she needed his support, he cowardly hid and felt sorry for himself. I would put this main character on a par with the most disgusting main characters from stories about NTR and betrayal. I probably think so because I've never been in his shoes and didn't have that kind of character. But damn it. If you don't want to give something to someone, then you have to protect it and fight. In many ways, the characters in this work were a surprise to me.