Child of an abusive dad chiming in here, fwiw.
The best thing my mother ever did was leave my dad for us. He was extremely abusive, psychologically and verbally. He tore my mother down on an almost daily basis. He called us names and verbally berated us anytime he felt like we didn't live up to his standards. I'll never forget the day she stood up to him. At 8 years old, I told my mother we needed to pack our things and leave. It wasn't the first time she had tried, but it was the first time I spoke up. I had been on anti-anxiety medication since age 5. We ended up having to live with my grandmother because my "dad" refused to pay child support. The one time my mom pushed the issue through the courts, he threatened to kill her (in front of me and my sister, and his parents, and a courthouse full of people). At 34, I still suffer from damage he did to us, but through therapy and support, I moved on.
I'm telling you this so you'll understand that your kids are being negatively affected by this right now, whether you can see that or not. They may internalize their stress and you might not see it for years. But rest assured, they are being affected by every bit of what is going on inside the home. I know from watching my mom how hard it is to leave. Abusers don't change. Period. You need to start with any available resources available in your area for abused women. Work your way out from there. The first step will be the hardest, but many women before you have done it. You can do it too. I'll be praying for you. It isn't an easy road, but your sanity and safety (and that of your kids) is the important thing.