When is a PFA necessary ???

I’ve been dealing with a man for 6 years we have a 1 year old child together. We currently are no longer together and I want to keep it that way. The mental abuse I had to deal with was draining. I ask him to watch our son while I go to work Monday and Tuesday nights which he agreed. Last night I got home and I was about 40 minutes later from my normal time because I got held up at work. When I got home he pushed me into the wall and slammed me on to a chair. He screamed at me saying “you knew I had someplace to be. What didn’t you answer your phone coming I here all late.” After he left o text he please don’t come back here because I will not be his punching bag. He text me back that o was a liar and he never put his hands on me. He said he will be back tonight to watch his son. What should I do? I don’t want to keep his son from him but I don’t deserve to be treated like this