Im in love with a boy who seems to be bratty, selfish, immature, and controlling at times?

No you are not wrong for doing that, because your not in a real realationship with your ex so why is he getting mad, you need to tell him that he has nothing to worry about because you and your ex is just freinds, but its best to stay at the house sometimes, to let him know for a fact you are not cheatin or anything. If he brings up something you did in the past just bring up something he did in the past to just go along with him