My interpretation: He gets angry at his girlfriend whenever she asks for a compromise in the relationship. He thinks "Why should I change how I am for her?" He's too "scared and stuck in his ways" to even think about whether she is happy or not. Whenever she leaves him, its "almost easy" for him to get her back. He makes false promises, begs and pleads, and then when she's back, nothing changes. He treats her the same as before again. Then one day, it doesn't work and she won't come back. He's ashamed of how he's manipulated her, bullied her, just to make himself happy. He knows how he made her feel and regrets everything he did. He realises he's very selfish but now he knows he can change. He wants to change to keep her, because he realises that he loves her. But he can't get her back. He's pushed it too far, and she doesn't want to give him another chance to "make it right". He's lost her for good, and is remembering what his mother told him about how to treat women, wishing he had listened. He's exactly like my ex.