Can I leave?

For starters, we are not legally married and have 2 children. I have come to realize how toxic my partner is, the degrading comments, the outrageous expectations, the limitations that he has put on my to communicate with people, the spying, lying, the cohorced sex, and the drinking. This has been building for years and I gave him the benefit of the doubt. Until he got drunk and started throwing things at me, calling me names in front of the kids, hit me in front of my kids, but its my fault, my attitude and ungratefulness makes him drink, makes him call me names, makes him leave and stay home for days at a time. In always the problem in his eyes but now I see its him. There is a 7 year age gap between us and when I was 17 I didn't see the red flags of a 24 year old taking interest in me and getting me drunk. I turned 24 this year and looking at 17 year olds and imagining a relationship with them makes me want to vomit. I see it now, I see the abuse and I want out. Since we are not legally married can I move to another state and file for custody there? He has emotionally abused me, financially abused me, sexually assaulted me, and now is physically abusive. Is it legal to take the kids and run?