Why pretend?

Why do you hate me so much is it because im with him and not you?
Why do you try and get me to hate you is it to and make it easier for you to get over me ?
Why do you act as if you couldn’t care if I died tomorrow when I no for a fact your heart would die the second I did?
Am I just being stupid for thinking that you have and will always care about me?
I need to no because it might be hurting you but it's killing me.