Yes I do this and sometimes I wonder why, other times I know why.
We have had a very stressful year, with moving to Australia (he is Aussie so for him it was going home) and me having to adjust to the whole thing, including leaving friends and family (i.e. RL support network) behind. We have a 2.4yo DS - I am co-sleeping with him again, despite having had him trained to sleep on his own in his own room in his cot from between 6-18mo. DH sleeps on his own "because he needs his sleep" .
I get down, I get tired, I get depressed. And then I get ultra snippy and some days I can barely say a civil word to him.
Sometimes I just need time away too - several times I have been tempted to just get in the car and take off for the day, leaving DH to take care of DS by himself (except he never does, he always phones his mum to do it)
Some days he just takes it, other days he also tells me he is sick of me talking to him like he's a piece of shit. (Are they the same person, I wonder?)
What he never seems to do (and maybe this is my fault, maybe his) is to actually address the situation and ask me if there is anything he can do to help me, or that would make me feel better/happier/less irritated. It doesn't help our case that he seems to positively delight in winding me up, I tell him he's doing it, he knows he does it but "he just can't help himself" - so IMO he often deserves the snippiness.
There is simmering resentment on both sides, something we need to deal with as it is slowly poisoning our relationship.
You have just had a baby, you are tired, worn out, hormonal and possibly slightly PND (Have you been checked by the HV?) and your DH needs to do what he can to help you, rather than just getting all huffy and "poor me" about it.