I need advice!! Very important

So me and my fiancé have been together for nearly 4 years now. We have a son together who turns 1 next month. Here lately, and by lately I mean like ever since our sons been born, he acts like he don’t care, he’s cheated on me back when we first got together and he says the last time was when I was pregnant with our son a month before I had him. Well anyways I am to the point to where I want to leave! I have called my mom twice to come get me and my son I’ve packed our stuff and then always change my mind. I’m in love with the idea of having a family and being happy together. I just want things to work between us. But I’m seriously truly not happy anymore. He doesn’t help clean the house, he doesn’t help with our son. Which yes I understand I’m a stay at home mom I should clean and do it all and be okay with it but it’s not that easy. We have 3 cats and our dog with her 4 puppies inside. They tear the place up. But that’s not the point. Anyways like last night I was getting my son to sleep when out of no where he threw up all over me and our bed enough to soak my shirt and so I woke up my fiancé asking for help and he yelled at me saying I’m stupid because I tried to catch his throw up instead of running to the bathroom with him. And then today he yells at me why I don’t even remember I think it was cause I asked him to help clean the house but he wouldn’t do it. He calls me a terrible mother and stupid and retarded and tells me to go suck a dick and go fuck myself and everything else and I’m just sick of how he treats me. I told him if he don’t stop I’m leaving. He changed for a couple days and then boom right back to how he is. I want to get away from him but I’m scared to I guess, it’s just really hard to do with a baby. Not to mention we were trying for a second baby and now I have a week until I need to test. But at this point I’m just so done. My mom wants me to leave him so bad. She says my dad was the same way and idk what to do. I wanna just cry but at the same time I do love him and I’ve tried everything In my power to fix things but its not me that needs to be changed. Any advice at all is welcome!! Oh by the way tonight my dog with her 4 puppies, she was growling I wasn’t sure why, well I wake him up and he jumps up and goes over there to her and says I ought to punch you In your face and then he says you know what then he hit her so hard!! I said something to him about it and now he’s mad at me. It was all cause she had his bag of jerky that he left laying out. I honestly feel like if he can do that to her he is gonna do that to me or my son. Please help!!