Taxes +baby daddy

So I guess I need some insight on what I should do. My daughter was born in June of 2019. Before she was born we decided I would get all the taxes that involved her. Now that she’s here , he has asked if we can split it. So I tell my parents what I decide to do what my taxes and when I told them I was giving him half, they said it wasn’t a good idea. Keep in mind that this is the same man that pushed and pushed for an abortion. He said if I aborted he would marry me and we could get a dog. Thank God I never listened to him. But while I was 4 months pregnant he ended up texting this other girl saying he was single and asking about her sex life and told her he didn’t have any kids. That same night I found out about it we got into an argument and it broke part of my front tooth off. We moved in together in October and the same day that all three of us moved in, I found out he was sending pictures of my daughter to his ex. That led to a huge fight with him pushing me in the window and tackling me to the ground all while my daughter watched. Most times if I ask to watch our daughter so I can shower or do my hair he huffs and puffs. The last time he did that turned into a huge that involved both of our parents and now I’m living with my parents. In his mothers eyes, her son doesn’t do no wrong and anything I say about her son it’s “oh well that doesn’t sound like him” so I guess back to the question, I’m getting over 5k and I’m not a confrontational person and idk how to bring up to him that hey, I can’t split half with you. Or should I split half with him? Or maybe a lower amount?

Just wanted to add something in

My dad had to go to his house and talk to him about him buying diapers about a month after she was born. He bought about 3 cans of formula since she has been born, and it’s always a different brand than we use from WIC because it’s cheaper for him. He bought her one Christmas gift but he never bought any clothes or anything. He isn’t on child support and nothing about custody involving the courts. He uses my food stamps and my car when needed.