My boyfriend and I have been together for 4 years now, we have a 6 month old daughter, ever since she was born, my boyfriend has been unusually angry at me over everything and I don't know why. I am scared because our daughter had gotten shots the other day and he was frustrated with the baby and was pulling her legs and hurting where she had gotten them, sometimes he smacks her hands and makes her cry, or spanks her bottom, too hard, and I tell him to stop, but he doesn't listen. He says she needs to learn discipline but she is only 6 months old, like a 6 month old knows what is right and wrong. I don't know why he is doing this, he has never been like this before. I don't know what happened, or what to say to him.