Wtf do i do? :( babys dad dating ex friend?

okay so a little over a week ago my ex boyfriend went missing for like a whole day after our 9 month anniversary and he begged for me back for couple days but then i talked to his cousin whos a backstabber, and she was supposed to help me out, instead she lands up letting her friend g out wth him and he usually comes crawling back by now but he hasnt, i know hes having sex with her and **** but see he has a baby wth me, his whole family hates me and hes ALWAYS the type to beg for me back but he hasnt done that its been close to almost a week that he hasnt called, i know hes living with his cousin and that girl is there, but he al of a sudden doesnt care about me or his baby at all, and he fought so hard for our relationship, and he was IN LOVE with his baby now hes denying its his and doesnt give a fck about me at all, you think that i need to give him time and hell be back or do you think that hes gonna land up coming back? cause i love him and idk wtf to do already, but i know its hard to believe he changed his mind out of nowhere an just doesnt care.