My fianc� gets so angry at the smallest things. How can I help him not get so angry?

My fianc� and I just had a baby together and we are both so happy to have her. When the smallest thing doesn't go his way, it's like he completely changes. He throws things, screams curse words, and somehow finds a way to blame me. He does this at least once a day. I feel like I am just waiting for his next outburst. It's hard for me to be happy about anything because all I can think about is what will happen next that will set him off. He is a great dad and supports us. When he is not angry he is very sweet. I am always calm and try to be as reasonable as I can when he gets angry. I normally just agree with whatever he says and not say much. Even though I don't show it to him, the stress is really starting to get to me. I am forgetting things more easily (ESP since the baby is here, bc I have her to think about now) I can't always remember every little detail that he wants me too, which just makes him more angry. He is so scary when he's angry. He takes it to another level. Trying to be perfect all the time and it never being good enough is taking it's toll on me. What can I do to help manage my stress and keep him less mad. Talking to him about this is out of the question, this would make him lose it.