Talk to your doctor, sweetheart. Even if he or she doesn't think it's post-partum depression, it will do you a load of good to talk about it. But it does sound like ppd, don't be embarrassed!!!!!!! it's hormonal and not a character failing.
My husband stayed home the first week after I had the baby, when he went back to work I went into a bad depression for a few days. I was so sad and upset. It leveled out for me. A lot of it had to do with how overwhelmed I was, I was adjusting to two kids, a ton of appts, and my sons school, plus lack of sleep. I would give it a few more days and see if you come out of it at all, if you don't I would talk to your doctor. Sometimes it takes a while for your hormones to level out from the pregnancy, and lack of sleep and adjusting to a new baby is hard. If you don't start feeling better definitely talk to your doctor, depression after having a child is very common and nothing to be embarrassed about, you'll get the treatment you need (if you need it) and it will all pass. Good luck hun, and congratulations!