VENTING.. Ex bf already with another girl while im 8w5d pregnant with his child

After a year of ALOT of fuckery and heartache, Ive decided to finally let go of my ex boyfriend who im currently 8w5d pregnant for. Its been about 3weeks now and in NO TIME hes already posting another bitch pretty much naked with him on his snapchat... this wouldn't be so disgusting to me if I wasnt pregnant with his SECOND child and if the break up wasn't completely his fault.. our first passed away at 20w and he was barely there with me for the pregnancy, and was only around for about 3days after the loss (wasn't even with me in the hospital when I gave birth to our son stillborn) before disappearing and being a complete bitch. Should of NEVER forgave him from then, but when he came back around he apologized and explained he had to deal with the loss in his way which was not speaking to anyone and I couldn't respect that he was such a  bitch but understood everyone deals with loss in their own way. After getting back together, we were unseparable, he pretty much lived with me we were together everyday but started having issues when I would look through his phone and see him flirting with bitches.. He swears its business and says hes with me everyday when would he have time to cheat butthen would   some nights go out with his friend, and not call me to tell me hes not coming home and I wouldn't hear from him until the next day. I explained to him MULTIPLE times how much that shit bothered me nd to just call or text to tell me hes not coming home for the night but he'd always say ''its not that serious''. Well my LAST straw was after he knew I was pregnant and after coming home from doing the same fuckery i told him i dont like, made plans with me to go to dinner but his friend called and wanted to chill so he said he'd just be in my parking lot.. Long story short he never came home that night, NOR did he answer any of my calls or texts for about 2w and even took it a step further and CHANGED his number.. That was the last straw for me I broke up with him and haven't looked back since and since then his sisters have came to my god sister asking if shed like to come out with my ex and his ''friend'' which was a girl... And he's literally been down the road from me everyday and wasnt saying shit to me... He obviously thought that was ok cause after cussing him through text he's only came to my house to get his shit, after telling him i don't have it he's brought a bitch to my house to pick it up (she was in the car never came out and I found out later) has literally tried to fight me and has NEVER inquired about his child that im NOW pregnant with... Hes also never acknowledged or apologized for not contacting me in the first place... After all was said and done, He was on welfare off my address and I took him off and because he's super livid he wont be getting money because of the one person who actually had him and he decided to diss, now hes doing this... I have a feeling its his first child's mother but regardless of who it is this hurts im pregnant and alone while hes doing all this fuckery. I don't deserve this.. Ive been so good to him, better then ive been to myself.. and have been there for him even though he wasn't always there for me.. I hate him feel like knocking him out and really feel like just saying fuck him and not allowing him to see his child since he doesn't even give a fuck to inquire how im doing while pregnant with HIS kid anyways... Ugh im so frustrated.. any words of encouragement or advice would be nice