thought it was you. don't worry, people out themselves sometimes - it happens.
if he won't talk about it, could you write him a letter? something along the lines of:
"I know that it's kind of odd me writing to you, but I really need to talk about this, and I feel that the best way to express myself is to put it down in writing. you know that before ds was born we had a very active sex life, and while I was pregnant with him we agreed not to have sex so as not to jeperdize the pregnancy. But it wasn't just sex - the affection seems to have gone from our relationship as well. when I try to kiss you I only get a peck on the lips, never a full-on kiss any more, and I'm no longer pregnant, so there's really no need to not be intimate any more. Thing is, every time I try to get close to you, you seem to have a reason not to recipricate, and it's left me wondering if I've done something, or whether you just don't feel the same about me in that way any more. You know that ds is our number 1 priority, but you're my husband and that hasn't changed, and I haven't stopped loving you or wanting you just because I've had a baby. It's still important for us to have time for us as a couple, but if you don't want to be with me like that then it does make me feel rejected. please be honest with me. I would rather know if you don't fancy me any more, rather than having to keep wondering".
get a babysitter, cook him a lovely meal, and then give him the letter while you're cooking, and then you can talk about it over dinner. if he can't talk, ask him to write. it's often a lot easier to put how you're feeling/thinking down on paper than it is to verbalize it. But you do have to talk about it, because the longer it continues, the more it will become the norm iykwim.