Advice please...

Just got in a fight with my boyfriend. We both use MY phone, and last night I went through his phone that he only uses on wifi. I found porn, and messages from when we broke up for a week, where he was messaging people off Craigslist. I didn't say anything about it. He wakes me up and starts getting mad bc I went through his phone. I didn't say anything because I didn't want to fight. Then he just starts talking crap and I told him to shut up. He wasn't taking anything serious. So I got my daughter and was about to head to my moms for awhile to cool off. He hid my phone and took my keys and He wouldnt let me look for anything. I pushed him out of my way and he grabbed me by the neck and pushed my down on the ground, he was still on top of me while I was on the ground and I started screaming bc I've been in an abusive relationship before. He covered my mouth and nose and I started hyperventilating. I finally got up and he got back in my way and I started hitting him and he grabbed my hair and threw me on the ground and when he did that my head turned more that it should have. I started hyperventilating even more and just laid there shaking and he layed down beside me and told me to just breathe. after all that I got my stuff and was about to leave and he started begging me to stay. He grabbed all my pills and went into the bathroom to overdose. I tried to open the door but I just couldn't and I told him if he over dosed I would call the cops. He came out and he gave me my phone and I got my keys and left. What do I do??? I know if it's this bad it will only get worse...