Girl, your couldn't-care-less attitude it's killing you. You're just lying to yourself. Things affect you: hurt you or make you happy, but you behave as if they weren't important.
Everyone knows that, so why don't you change? CHANGE!
I mean you’re not being yourself; you are not being the main character of your story. You are being someone else... a cold and calculating person.
So, you have two options:
Surrender and keep living like this or finding yourself again and being happy and not afraid of showing your feelings and emotions.