Single mom... again

Little rant, just really need to talk. So yesterday I caught my SO cheating again. We had been together for almost 2 years and have a child together and one on the way. Plus I have a child from a previous relationship that he pretty much stepped up and became the father to. Within the time we were together he cheated on me twice and I caught him texting other girls countless times but I stayed anyways hoping to make it work (knowing it wouldnt) and yesterday was the final straw. As I was getting our stuff together he started throwing a fit and trying to turn it around on me. He was screaming in my face and tried to hit me as I was walking out to the car to get the kids carseats. When I got to the car he walked out with our daughter and got in the driver seat and tried to drive off while holding her. He finally got out of the car and slammed the car door on me while I was unbuckling the carseat. Now we are in a custody battle and I have a restraining order on him. Which he probably won't even get visitation with the kids bc he can't pass a drug test.