If you just had a baby but also breaking up due to cheating

How did you effectively co parent? Like how do or did you keep it together while your heart was breaking due to how your significant other did you wrong? What helps to get you through knowing you still have to deal with the cheating bastard since you have a child with him? Our breakup is still fresh but I think he is going to get into a relationship with the woman he cheated on me with. So do I have to be cordial with a woman that knew he was an engaged man and be okay with her being around my kid? I know you will all say I can't blame her and I'm not it's just I know for a fact she knew about me and he is a ruthless bastard. I'm trying to be a strong woman but this type of betrayal hurts 😓

Edit: I definitely want our baby to have him around and I know I can co parent but I get a lot of backlash when I try to dictate who I don't want my baby around. At the end of the day I can't control who he have our child around when she is with him. But it's really fucked up to cheat and then get into a relationship with the girl and then expect me to be cool with her and for her to be around our baby girl. Ugh