Sadly, the sleeping-through-the-night thing was a one-off, and he’s back to his 3-4 hour schedule. I have been trying to push it to 4.5 hours minimum between night feedings so sometimes when he wakes up before then I take him into the nursery and calm him down in there. He’ll doze while I rock him, but forget trying to put him back down in the co-sleeper.
It seems like he’s having more trouble going to sleep, too. Last night he didn’t go down for good until 11:45. Woke up at 2, fed him, then he slept until 5:30. I was too tired to bring him into the nursery so I just fed him and went back to sleep. He started thrashing around at 6 or 6:30 and I brought him into bed to get another hour of sleep.
Luckily, he is still cute.