Don’t know what to do!!!

So I’ve been with this guy (Mark) for over 6 Years we have two kids together and just got married May 2017. We have always had problems because of he’s jealousy. There was a guy (John) that I used to work with, 4 years ago, that would sent me text all the time and of course my boyfriend would get mad. I cut the communication with (John). Well ever since we got married I don’t feel happy. We’ve had issues long before this but ever since we got married it’s been bad. He even told his family he only got married because I kept asking for it. He got mad when I didn’t change my last name. To me it wasn’t a big thing... like okay? We’ve been together forever and everyone knows that plus is not like I’m showing everyone my ID. He says that I can’t prove I am married. I don’t feel like I need to prove anything to anyone. He’s always accusing me for cheating. Always calling me names and he always does this in front of our kids. Our oldest knows what’s going on and starts crying I know it’s affecting her because even her attitude has change. So I decided to break up with him about a month ago... I really don’t want to keep going through this... I feel like I have lost all my respect towards him. He just won’t accept it and is still blaming me for things. He won’t leave the house either. It is my parents house. And my parents think I’m crazy and should stay with him. The last thing that really hurt and made me realize I don’t want him was when he asked me to keep having sex with him and that he would even pay me!! Like wtf who does he think I am??? Am I crazy for trying to leave him?