What exactly went wrong here?

Its is very obvious, he is falling in love with you. But since he saw that you were still dating then he was trying to push you away, because he probably felt you weren't taking him seriously like he was. When he realized he hurt you and made you cried he felt bad and tried to apologize. So don't take it personal it was his ego. A man will never talk to you about feelings, you just have to pickup on signs. He asks you questions in a subtle manner because he wants to find out what is going on with you. He is not going to tell you about his feelings because he doesn't want to feel vulnerable. So if you have feelings for him I think you are going to have to take the first step.