Dealing with your spouse

I just found out I'm having twins and I couldn't be more excited! It's literally the only thing that keeps me going lately! I'm not sure why but I really hate my fiancé, I can't deal with anything he does! He's constantly messing up and I feel so bad that I feel this way(for my babies) I don't want my babies to not have mommy and daddy together but at this point I'm just so unhappy I wish I wasn't with him.. Idk what to do.