In a word, guilt. When you cry, he still feels like a hero and he can save the day (in his twisted mind, he really does feel like he's a good guy here.) But when you're doing great, it validates his twisted view that everything is your fault because everything is going your way. I'm convinced they really do want to punish you, because you're the bad guy -- wrong as in unsuitable and incompatible for them, wrong in the way you've treated/controlled/bullied/whatever them.
They are emotionally all over the place, so don't get sucked in. Act with authenticity -- but pull yourself together.
