"Heaven has no rage like love to hatred turned, Nor hell a fury like a woman scorned"
--William Congreve, 1697
Few things are as deadly to the male ego as the utter bitterness, hatred and revulsion that a scorned woman levies at the man she once said "I love you" to. Often experienced at the already lowest point in their lives, spurned men struggle to understand just how it's possible for a woman to do a full 180 on a relationship and see you as such a vile monster.
Thankfully you're here on TRP where there are answers.
Men typically do not behave in the way that women do when bitterly breaking up. A man might choose to completely cut contact, refuse to talk about her, or merely pass her off as a "bitch". Rarely does a man go so far as to try to destroy her life after the fact.
Yet this is a phenomenon we see with women. Not all, mind you, but a disconcertingly large number. Many divorced men in this very sub will tell you how the woman they fell in love with, shared a partial lifetime with, raised children with, somehow became their most bitter enemy. Took away their children and refused to let you see them, took away their assets and their ability to support themselves, vilified their name and character to everyone who would listen. They made damn sure that friends, family and future girlfriends knew that you were the villain.
Most men just want it to end.
The reason for this is that women view male SMV as a function of status and dominance. The very fact that you were enough of a loser in her eyes to warrant a split means that your SMV is the lowest relative to the males in her life. Note how this differs from the male experience; When men leave shitty women they often still have decent SMV -- chiefly looks and ability to be a mother for children. They may be a shitty person, but that's a fraction of her SMV. Not so with the way women perceive men.
Imagine if everytime you broke up with a girl she instantly gained 300 lbs and her face became covered in horrendous facial acne. You'd be disgusted at the thought of being around that woman, much less touching her.
This is what women experience when leaving their men. By being a weak and pathetic man in her eyes you are absolutely the least attractive person imaginable. Why would she give a shit about you?
Men and women are different. If you expect the time, effort and energy you put into a relationship with a woman to matter after the fact you're likely in for a rude awakening.
Take care of yourselves out there.