Feeling hopeless

Me and my boyfriend have had a rocky on again off again relationship for the past 2 years. When we found out i was pregnant i was very unhappy and have been struggling with forms of depression my whole pregnancy. Ive been having a hard time feeling happy or excited about having a baby. Today we got into an argument over nothing. I was asking him why something hasnt been done and ive been literally asking him to deal with it for weeks. Hes currently not working and on workmans compensation but hes more than fully capable of completing this task. Im still working full time on my feet all day. I was questioning him about why it hadnt been done and he gets very disrespectful. I smacked him and he hits me back and we get into a physical fight. I hit him ans he hits me twice harder than hes ever hit me before. I have a bruise on the side my face and above my eye. He has a cut next to his nose from my nail. This isnt the first time weve gotten into a fight like this but the first time ive ever gotten bruised by him. Ill be 39 weeks tomorrow with his child and i couldnt feel more depressed. I dont know what to do. I have wanted to leave on and off for a while but not sure where i could go because its not just gonna be me anymore. Ive been an emotional wreck over the last few days. I had a break down at work on Wednesday and was extremely upset after my doctors appointment on Thursday. I feel like our relationship is extremely unhealthy and im so afraid to even be having a baby around in a situation like this. I cant help but feel at fault and hopeless about the situation. I dont know how to handle things i feel like ive never failed so hard in my life and i dont know how to make things right. He says i dont appreciate the things he does for me and i feel the same about him. I dont know how to fix this. Ill take any advice 😢