TLDR; I had a huge fight with my wife and she hurt both me and my daughter.
I got married to my wife 14 years ago and we have a lovely daughter (9 years old) who I'll call Becca (not her real name). My wife, who I'll call Anna (again, not her real name) has been lovely up until the last few months. Lately she's been blowing up a lot more over small things like forgetting to lock the door or falling asleep with the TV on. It's not just small arguments, but actual screaming matches where she gets physically angry (like clenching and unclenching her fists and raising her hand at me but stopping). She was never like this before, and I don't know what's changed. I feel like I could've dealt with this in private had she not recently dragged our daughter into the arguments.
Lately I feel she's been picking fights with our daughter for no reason. Like, as in randomly she'll go into Becca's room and start screaming at her for something insignificant like forgetting to close the bathroom door (because we have a dog that likes to roam around). As I mentioned before, it's not like she's quiet when she's screaming at our daughter. Anyway, I feel like she could just… talk to Becca quietly because it's not even big issues she yells about.
About the argument that caused all this, I was talking to Anna about the issue of how she yells at Becca and I asked her if everything was okay since she'd never acted like this before. She immediately got up and left without saying anything, and I thought she would come back until I heard her go into Becca's room at the end of the hall and start yelling at her for "causing problems." I followed after her and tried to get her out of there so we could talk about this, but then she slapped me. I asked Anna what was wrong with her, and Becca had gotten tired of her mother too so she started defending herself and me. Anna just pushed past me and stormed out of the house. I tried to call her multiple times but she didn't answer for 2 days. When she came home, she acted like nothing happened and it made me really suspicious.
Fast-forward to last night, I was sleeping when I heard our daughter scream. I got up and ran to her room to see the door had been kneed-in by Anna (as my daughter later told me) and I arrived in the room just in time to see Anna pin my daughter down and slap her. I ran over and pushed her off, yelling at her before picking up my daughter and fleeing out of the house. We're currently staying at a hotel, and Anna has been blowing up my phone with calls and messages. They range from apologizing to saying that Becca was a mistake and that she hates the both of us. I'm completely stuck on what to do.