Thinking about leaving my relationship

I’ll make this as short as possible, the last 3 years I’ve been seeing this guy. He always told me I couldn’t be with anyone else because I was “his” and I believed he wouldn’t get with anyone else either. He’s 28 I’m 23. So he got me pregnant a few months after we started hooking up, he has a son who was 2 years old at the time. So I was 20 when he got me pregnant and when I told him he told me I was too ugly he’d never want a baby with me and to get rid of it or he’ll hire someone to do it... a few days later he apologized for how he reacted but still wanted little to do with the pregnancy. I used to babysit his kid when he worked overnights and that was a main reason he kept me around. Unfortunately I miscarried at 14 weeks and after that things got worse, I was in an emotional state and he didn’t seem to care at all, he would still get with other girls and lie about it just to keep me around for his benefit. One night we got into a really bad physical fight at his house and after I left I think he realized he fucked up and started blowing up my phone telling me how sorry he was and he wanted to be with me and would do anything for me and said we can try for a baby in the future. Of course the fairytale sucked me back in only to of course end shortly after. Anyways this went on for 3 years and yes I know I’m probably stupid for not walking away but it was hard for me to walk away for whatever reason. He’s hit me and made me feel down about myself and would magnify my flaws times 10. A year later I became pregnant again and he handled the situation a lot better but told me not to tell anybody because he wanted his family to hear it from him not anyone around town. I waited until I was 28 weeks to announce. He didn’t tell his family until hours before I had our son, only his parents and sister knew. I decided after I had the baby I’d move with my grandma and we set up her extra room and make his nursery. It wasn’t until a few weeks before i had my son that he thought we should be together. My mom owns a home that she offered to rent to us so we took it. Soon after that I found out he was having sex with other girls while I was deep into my pregnancy. Literally until the month my son was born. I found some girls bra and underwear stuffed in one of his sweatshirt pockets. I never told my family about any of this but his mother met my mom and casually brought up to her things that have happened in the past as if it was no big deal. My parents were extremely upset and said they wouldn’t have let us rent the house if they knew the kind of past we had. A few months ago he got into an argument with me over furniture and punched me really hard in the arm and I was venting to my mom about it and she said she’s had enough and not going to let someone abuse her daughter especially in front of children and called the police. I don’t want my son growing up thinking this is all okay within a relationship so I started staying at my moms house. I got an order of protection and filed for custody. When I saw him in court I broke down and second guessed myself and dropped all the petitions and tried to work things out between us. Things got better. Last week at a family party he got drunk and started acting crazy because there was a guy there his age with the same name that I’ve known my whole life but never mentioned to him. He’s a family friend who is literally like family to me. I never thought to mention him and was never trying to hide him, there’s many people in my life who I’m sure I’ve never mentioned to him. He fought with me in front of my family and that really turned me away from him. He’s extremely possessive, needs constant attention and affection and reassurance. I’ve never been super lovey dovey and I like having time and space to myself but he wants to be together every second of the day. He gets mad if I don’t cuddle him at night. He wants to have sex every night and day a few times and sometimes it’s just a little much for me and he kind of gets an attitude if I don’t feel like doing it. He tries to distant me from my family because my son, his son and him are my family now. Anyway I tried to leave him last week and he had a breakdown swearing on both his sons lives that he’ll change and he sees how hes been and he doesn’t like the person he is. He’s been a lot better and definitely trying and keeps bringing me little “presents” here and there (like candy bars) I’m 99% sure he has an engagement ring for me and keeps talking about how he can’t wait to marry me and be with me forever and have more babies. But I don’t see a future with him. Everyday I want to be around him less and less. I don’t feel like I love him anymore. We have a lot more bad memories than good, I think there’s too much damage from our past for me to move on from. He was having sex with girls AT work! I’m constantly worrying when he’s working. He’s made me feel unlovable, like I’m unwanted and not good enough, not pretty enough, not skinny enough. For some reason I just feel so bad leaving and so guilty. And ever since my son was born I’ve done everything myself. I wake up with him I feed him I change his diapers bathe him dress him give him naps and play with him. I told him help from him would be nice but he said since I’m a first time mom and since he’s already had a kid, I need to do it on my own so that I learn.... he doesn’t hear him crying at night or just ignores it. He’ll see I’m struggling to do something while holding my son and not even offer to help and didn’t know I wanted help because I “didn’t ask” and he always expects me to make him every single meal and clean everything all the time. He’s the only one working right now and I understand I should be the one to pitch in with housework and I do, but it’s hard to do with a 7 month old and 4 year old. Especially by myself and everyday with no help. I’m afraid to leave too because I don’t want to have 50/50 custody, I would want him to get visitation because he doesn’t know how to take care of this baby. He works all night and sleeps all day. He favors his 4 year old. I’m okay with visitation because my son deserves a dad but I’m 100% his caregiver and it’s in his best interest to be with me. I’m just at a loss. Yes, this is as short as I could have possibly made this because I could write a book about things that have happened! I would love some opinions.