Oh dear. I understand that its frustrating for you. Don't be dishearten okay. Try to get your husband to drink lemongrass with just a little bit of honey. Hopefully the cough clear very soon. Because, you are full term. The baby might be seeing you soon.
Have him drink warm water very often, take vitamin c daily, use listerine gargle daily. Hope he recovers soon so he can join. Otherwise, no choice but to take the safer option
have him drink a ginger tea mommy I mean the real ginger slice it and boil and then put a slice of lemon it really helps a lot for your husband's cough.