8 mos pregnant, husband abusive

I'm 8 mos pregnant and am all but completely decided on leaving my husband for a couple of reasons. 1) he's been chronically unemployed for 5 mos for no reason other than he just seems in no hurry to work. He keeps saying he'll get a job but he doesn't follow through and I place most of his applications for him. 2) I don't think his abusive ways are going to change, verbal and physical. I've gotten a lot stronger dealing with the verbal side of things and I'm used to being called a stupid bitch, idiot, etc. when we argue and it makes me mad but I brush it off. But physically? Although what he does doesn't leave visible marks and he doesn't hit me with his fists, I just don't think I can deal with it anymore and I'm scared my son will grow up thinking that's ok, to grab, push and block women from leaving. I've been getting really fed up as over the last several weeks he's been spending a lot of time away and always tells me he'll be home at a time then that time passes and he gives me a new time, and on and on until sometimes it's 7 am when he gets home. I feel isolated and lonely and I worry about him and don't sleep well. He told me he was going to be gone again tonight and I got mad and was asking questions but what he was saying didn't make sense and he yelled very scarily at me and I started to cry. Then the people he was leaving with got here and I said no he's not going and he was enraged and stomped up to me. Instead of cowering like I used to I've started keeping my chin up and looking him in his face. He grabbed and pushed me by my throat and then told me I had gotten in his face when all I did was stand my ground while he charged me. He has a case being charged by the state from when I called the police at 19 weeks after we were arguing and he pushed me and then while I was laying in bed with my back to him hit me in the back of the head. I couldn't see what he did with my head turned but he said he "pushed" the back of my head, but I did get a headache as soon as he hit/pushed my head. He then blocked my attempt to leave in my car until I had to call his bluff and just keep backing out to get away because I was scared to leave the car. He still says I was wrong and hit him with the car but I didn't know what else to do as he had a car key and was trying to get in and he had taken my phone from me after hitting me. He did push me once while pregnant before that as well. I always want to believe he is really sorry or will really change. Things are blissful sometimes, normal at other times, but when they're bad they're REALLY bad. I shouldn't have married him. He strangled me messed up on alcohol and presumably drugs 2 years ago while dating, angering and holding me down on the bed choking me after he stayed out all night in my car and I told him I was leaving. Among that there were other incidents of violence including grabbing the steering wheel on the highway full speed almost causing us to crash, pushing me down, grabbing me by the neck, etc. I left him for almost a year and ended up back with him thinking the time apart really changed him. But he never changed. I married him, believing things would be different, we were in a blissful phase. But things aren't going to be different, are they? Maybe for a few months, maybe a year, but I never know when a question or conversation will turn to an argument or when an argument will turn into violence. My heart is broken because I do love him and the good parts and the talented and thoughtful and funny parts, the parts that are my best friend and the man I love and the father of my only child. But I can't count on that man to be there when I look at my husband, so I feel like I have to go. I worry he will go off the deep end drinking, or end up back on drugs. But I feel my tiny little son moving and I just love him so much and I think it'll be better for him for me not to stay even though he won't have his mom and dad together in the little family I always dreamt about.