Nothing makes a woman more unhappy than a man being happy without her. And even if his life actually sucks, it does not matter. What matters is if she thinks he is happy. This conclusion is based on facts conjured in morning mist or pulled from puffs of smoke outside a bar.
Not-made-up facts:
He should not have taken so much of her madness personally ("Why the fuck are you listening to your iPod while you are doing the dishes? DON'T FUCKING LIE TO ME!"). And he should have spared her more of his own (guys, never spit on your lady (unless it is during sex)). Those would have been real acts of love.
He misses her. She must miss him, too, because she does nasty things to hurt him the way she is hurting. It hurts him enough to know she is in pain, and that he could have done more to help her when he had the chance.
She would feel better if she knew how miserable he is now, and he will try to enjoy life even less just for her.