Scared of SO.

My SO and I have been together for almost 6 years. The first few years were so amazing. We have a 1 year old son and another on the way. This happened on Wednesday of this week. He had an attitude all morning. I had a couple boxes out that I meant to go through, he yelled at me to put them up and 5 seconds later threw them breaking most of the things in them. I told him to stop, he kept throwing my stuff at me, he even threw a decent sized perfume bottle at me (glass) it hit my hand and bruised my fingers good. I got up and he followed. Throwing a toothpaste box at me, I had enough at this point and threw it back and that's when it got bad. He started screaming at me to get out, he picked our son up and wouldn't let me get him, he kept him from me and he was scared. He was screaming at me so hard he was shaking and turning red all while my son was in his arms, which made me cry seeing how scared he was, I was scared too. I stopped trying to get him, and left him alone thinking maybe he'll stop scaring him, maybe itll calm things down, it didnt, he followed me to where I sat down and he told me to get up over and over. I told him to lower his voice, think about our baby, he grabbed me up off of the bed and made me get out of the room, i pushed him off of me and he gave me our son, went into our room and repeatedly punched the door. He was crying, probably because he tore his hands up, you can see the blood on the door. I was trying to distract our son and play with him without breaking down, eventually I got him to sleep. Layed him down, peaked into the room and saw him crying on our bed, I asked him if he was okay. I dont know why I even cared a little bit about him at that point, but I did. He was bleeding everywhere so I helped him wrap it up. I've been looking at apartments for my son and I. The next day he acted like nothing had happened, but hes been so rude to me. He never apologized, or anything. My son wouldnt even look his way for hours after that. I cant put him through that and I feel like I've failed as a mom already because it happened. I guess this is more of a vent post. Has anyone gone through this. Idk what happened to the guy I fell in love with.