I'm confused and hurt HELP!

I want a baby more than anything in the world. Me and husband had a mc a year ago and although I'm still hurting I feel like I'm ready to try again but my husband absolutely refuses. Then out of nowhere he asks me if he can have a baby with another woman who he's been seeing with my consent (I know that sounds strange please no hate) I don't know if it's ok for me to feel so hurt. I don't understand how he can be ready to have a child but I'm not. I don't know what to do and I don't know who else to turn to. Would it be wrong of me to deny him and his girlfriend a child? What if this is her only chance to become a mother or his only chance to become a daddy? How could I live with myself if I denied them that but how can I live with myself if I let them do it? Someone please help me and please don't speak badly about my husband