Why is he mean after break up?

My SO broke up with me out of no where after a year and a half. We both stated and acted like we were going to spend the rest of our lives together. We broke up 3 weeks ago. I have done nothing wrong during the break up. We didn't talk for those 3 weeks. We recently talked on Easter and he told me "I don't want anything to do with you." Is he trying to hate me to get over me? Or does he genuinely just not care?