For me, the blues hit on day 6. Both kiddos were having a cranky morning, and I was at the height of nipple pain and engorgement, and DH was on his way out the door for (yet another never-ending grad school) class. I said something REALLY mean to him

:, burst into tears, and that scene pretty much replayed itself all day long. Urgh.
It's been better since then. And overall, it's been better this time around than it was with DS. I think it's because having #2 isn't as much of a shock to the system as having #1 was.
Hang in there, mamas. It's all normal, we're not crazy, and it won't last forever!