Abusive relationship

I’m gonna make this as short and simple as I can.. but my bf and I have been together for over a year now, almost 2. We share a 4 month old daughter, car, home and money and he has kids and I have a son who is also in the picture. Our relationship has been pretty interesting to say the least since it’s started. Always something good or bad. I don’t wanna get too detailed, you all get it. We fell in love and so on... well, just like any couple we fight. We argue. We disagree. Well, ours aren’t normal. Or at least they shouldn’t seem to me but they happen so often it feels normal. He has such bad anger issues.. I believe he’s bipolar... he’ll get so bad he’ll say things like, no on will love me if I leave him, no one will want a woman like me, my son has a bad role model (because I smoke cigarettes) he calls me names, tells me our home isn’t mine and if it weren’t for him I wouldn’t be so well off in life, he makes me feel like I am nothing without him... honestly. When we argue, he calls me crazy and tells me their my fault and I find myself believing every word. He gets physical now... he’s cracked my wrist, broken glass where it cut my face, chocked me, twisted my arms and legs, shoved me and just a few days ago, he got so bad he choked me so bad I blacked out and believe I even had a seizure because when I came to I had no idea where I was and my touge was bitten and bleeding, then he banged my head so hard on the tile floor several times 3 days later, I still have a migraine. I know it sound obvious. Leave him. He’s crazy. But all at the same time, this is the same man who has fought for me when no one else did, put up with me, saved me, loved me and cared for me in ways I never knew. But also, I’m now asking myself is it worth it? Is that the man I used to love and now this is the man I’m stuck with... again, I know it sounds simple.. but idk what to do. Idk how to escape this and idk where to start. Idk how to make it better or feel safe with or without him. If I leave, I not only leave him but my house, my job, his kids and the life I’m used to. Things get harder for me. Again. I want to leave. I just don’t know how to. I know I sound stupid but I’m stuck and I just need to hear other women’s stories or experiences to hopefully push me in the right direction. I know what I want I just don’t know how to get it. I want out so bad but I’m so damn scared.