How do u know it's an abusive relationship?

Hi. I'm engaged, me and my SO have a 9 month old child and we've been on and off for over 2 years now. But everytime I try to leave he threatens to kill himself, and die and he talks me down saying I'm fat and my stretch marks are ugly that no one else will want me. As well as call me a slut and tell me a lot of mean things, to the point I don't even leave the house because I'm so disgusted with my body. He's an AMAZINGLY father, he loves our daughter. And we have amazing moments where we just talk and laugh and we connect like soul mates. But idk I want to leave I just feel trapped and put down constantly to where I don't even want to speak anymore cuz I hate my self so much. But he's a great guy and I love him and he loves me and he doesn't hit me or anything I just don't know I need advice. I'll answer any questions 😕