How to get him to stop asking me a million questions and only listening to half the answer?

My boyfriend and I have had a great relationship for over three years. We are now expecting our first child. He is a very complaisant man and that has always been okay because I am very high strung and work a lot of long hours. The fact that he is extremely mellow bordering lazy helped me to relax occasionally. He has this new found hobby of asking my a million questions at the most annoying times (while i am sleeping, watching TV, on the computer). I realize he is a nervous wreck and I have done my fair share of adding stress; I bought my own house because his is a do it yourself disaster in a very bad area. He also just quit smoking. The worst part is after he asks me questions that i feel like weren’t important he doesn’t listen to the answer. I have a perfect example below…

A: What are you going to buy at Lowes?
M: Paint
A: What rooms are you going to paint?
M: Kitchen, family room, and upstairs bathroom
A: Are you going to paint the living room a shade different than the kitchen?
M: No.
A: Well you better get 3 gallons for the kitchen.
M: I won’t need that much. I only used 1 gallon for the bedroom here and that space isn’t much bigger. I can always buy more after.

(The questions didn’t stop there… don’t want you to lose your sanity)

The next morning at 5:45am while I am still in bed he starts talking about what day are we painting the bedroom of the new house. I try to explain to him again that is not one of the rooms I am planning to paint. He gets mad and starts saying I keep giving him different answer every time he asks me a question. I just wish if he isn’t going to listen to my answers he would stop asking questions. I don’t know why he even cares he isn’t painting the new house. I know he is trying to be supportive but I wish he would do it quietly! HELP