What is my husband's problem?

My husband gets upset when our 18 month old son makes a mess when eating, like if he throws his bowl and accidently gets food on the floor and yesterday he got a little applesauce on the wall. My husband was freaking out and was over there trying to clean it up. I don't like when he does this either but my husband always makes mean comments, like "good thing your mom is here b/c if it was left up to me you wouldn't get anything else to eat" or "you're gonna eat crackers until you are 10 yrs old". Then I get p*ssed off & we get in an argument. He has just recently told me that he doesn't want another baby. We were going to be trying this month until he said he wanted to hold off a couple of weeks ago. I was so disappointed. :( He has told me more than once that he loves our son with all his heart but he isn't really a "kid person". We are getting to a spat it seems like once, if not twice a week sometimes because of all the negative things he says. I know he loves our baby..but geez he's only 18 months he doesn't mean to do some of the things he does. And as much sad as I feel about not having another (b/c I would LOVE to have a girl) there's no need to do it because he doesn't understand things and he gets too impatient and I guess it will only cause more problems. I just don't get why a couple of months ago he was so ready to try for another, but lately he is being like this. I'm so scared that if we have an "oops" (i don't plan on it but u never know- the pill isn't 100%) he will be upset and I'll feel it's all my fault! What is his deal??