Fiance flaking out last minute at 39 weeks?

He's been so good the whole pregnancy but last night he just tripped out. I know he's stressed out and is freaking because the nursery isn't done yet, he doesn't have the crib together, and his Mom is coming and I just can't clean the house like I used to. I feel bad for him but I wanted to blow up at some of the things he was saying (It was a very childish "boo hoo, me, me, me" conversation on his part). I tried to take it with a grain of salt but to be honest it really made me mad. How should I handle this and help him with his stress without blowing up and strangling him? Thanks.