If he can say something to you and it ruins your day or causes your emotions to change for any noticeable amount of time, he is in control of something. Indifference is no emotion. If he speaks to you and it causes anger, that's not indifference. If he finds another woman and it causes jealous feelings, that's not indifference. If his actions (not responding to a text) causes frustration, that's not indifference.

I've learned that healing is about the damage caused. Indifference is about the scars that are left behind, accepting them and knowing you can't change how the scars came to be you can only change how the scars affect you. And not letting them affect you allows you to be indifferent.

I hope that you focus on your relationship with yourself. From an outside perspective, saying your choice to relax vs drinking on NYE was lame and kicking yourself for being taken in by promises are forms of self criticism and self punishment. You don't deserve to be criticized and punished.