Is it possible that it's not something that happened, but something that is coming up?

My kids, DS especially, go through June madness every year (with an echo before Christmas). Big transitions stress them, even transitioning to something as wonderful and gleefully anticipated as summer vacation. We have another week of school left. Over the month, I've watched the volatility ramp up, and the ability to deal with the tiniest iota of adversity - or even the slightly unanticipated - plummet. They'll continue to be nuts the first week of vacation, and then we will all slowly drift out of permanent red alert as they settle into the new normal.

Do you have any big transitions coming up, like finishing daycare or preschool by any chance?