Fiancé seems odd about wedding

So my fiance one day acts happy about it and the next will hardly talk about it if someone calls to ask us if we need help. He also has been acting depressed now that it’s closer (it’s at the end of this month) I’m just scared and I have asked him but I feel like hes not telling the truth. I’m frustrated because I deserve someone who is happy and wants to marry me. I’ve never indicated that he’s trapped I’ve given him lots of chances to tell me how he feels about it. We have a daughter and here recently he’s been cumming inside me and I feel even more lost. Why would you want two kids with someone you don’t even act happy to marry? It makes no sense?… idk what to do because he changes the subject if me or anyone else tries to talk about it?