Need help😔 advice please

So I’ve been with my boyfriend for over 2 years now. We have 2 kids together and another on the way. I have 4 kids all together and currently pregnant. This relationship has been so rough. When we had our first child together he was going to gas stations and being sneaky he talked to an ex he had sex with before behind my back and hiding it from me I found out from my own sister because it was her best friend. Still to this day he hasn’t told me what they talked about! And he lied to me what he was doing at the gas station he goes from looking at Walmart to watching porn because he got bored and didn’t beat off to looking at rings and I have trust issues from it 😔 I’ve tried my hardest to gain my trust back and it’s so hard because I don’t know the truth. He’s starting to get awful towards me and brings up my mother who was killed and tells me why don’t you stop crying about your little mommy and it crushes me because she was my best friend my go to person and ever since my mom step dad sister and nephew were killed my life has never been the same and he knows that! My son wants his mamaw everyday and he literally tears me down with it! Well tonight we got into it because he’s trying to put me down and call me worthless and that I’m just a sob story and I want people to feel sorry for me when I don’t have any family really but my dad and sister because everyone got mad and pushed me away from my moms side because I said the guy that killed them deserved what he gets it was a cousin that killed them all and his mother was DEFENDING HIM😭 but my boyfriend always uses that to get under my skin. He’s put his hands on me before like grabbing something or twist my wrists but tonight he just overdone it. He was mad and talking bad to me and I was crying my eyes out so bad I started puking and peed all over myself from all the stress I’m under and I’m in early pregnancy! He grabbed my wrist tonight where it left welps and I slapped his side so he would let go😔 he left after and went to his grandmas house and told them I did this and that and lied so much and didn’t tell them what all HES DONE TO ME! And then his grandma comes at me saying I’m using him for a place to stay and his money and for food when I contribute to this place too! I get the diapers I get the food he pays the bills! I do everything for this man! Im a stay at home mom and I cook and clean and do everything I can for him while taking care of the kids and I never get breaks I don’t have nobody to watch the kids or help out since my mom passed away and I don’t know how much more I can handle with all of this with him😔 it’s like I’m not strong enough to leave 😭