8months & left to do it alone

Hi guys I’m currently 8 months pregnant & my ex bf of 3 years left me at 8 weeks pregnant , it

Wasn’t til I was 20 weeks that I found out he left me to be w somebody else . Fast forward the girl has constantly talked about me n my child on social media & my bd is so In denial about it & think she does nothing . Well now with me being 33 weeks he wanted to talk which is his first time seeing or talking to me since 8 weeks , He says that he bought our son stuff but he will only use them when he’s over him n his gf house ( my personally I think I would be a idiot to let my son around a female that doesn’t like me & have constantly talked about my unborn , why would I trust him around you ? ) n that if I didn’t let him see his son he was taking me to court . I don’t want my son around him bc he has constantly told me he was going to have his family n gf beat my child outta me or simply would tell me he could careless about us . He also said he loved Me deeply n tried to hold me once I started crying historically . After being told the gf was pregnant n the reason why he cheated n left me . It just hurts me because you never gave my son the chance to experience having a family & you never gave me the chance to experience being happy in my pregnancy but now your giving that to somebody you cheated on me w ? I know I shouldn’t be said but it sucks feeling like the only type of family my son has is me . And if he do take me to court could I fight him trying to get joint custody of my baby if I have the messages from him , his gf , & family threaten me n my unborn & constantly saying they would fight me & beat him out of me ? How do I deal w my emotions when it’s just been me & my son ? What do I do I’m only 21 n I feel like I’ve been out thru a lot these last 8 months emotionally & physically 😞