What is Going On?

She had 4 pieces of toast for snack. He had two cups of yogurt--not containers, actual measured cups. And they are crabby, whiny, discontent--having trouble sharing and taking turns, unable to entertain themselves, tired of playing with me, getting frustrated--which leads to throwing things, family time-ins, and time-outs. Is it the letdown after Gommie's visit? The excitement of Mama's return? Disenchantment with our normal routine? A growth spurt? A virus? Sleep deprivations (though, they've been getting a relatively healthy 12 hours, with some interruptions; I haven't and am grumpy and tired)? I thought yesterday was bad. But today has started off even worse. I had even changed a few things today, thinking it might help: yesterday we had lots of family projects, today we've been doing freeplay; yesterday, we watched some music on tv first thing in the morning with Mama, today no tv right away; it was raining all day yesterday, today it's nice so we could go outside (but haven't. They don't want to get dressed and I'm not ready for that battle--if they want to go out, they can get dressed). They want computer games but but that's a Mama thing. They want Gommie but she's gone. They want to go to school but that's not for 6 weeks or so. They want to go somewhere but, in a relatively rare turn of events, I don't really want to take them anywhere because they are ill-tempered and not following directions. Though, I did say we could go to the library since they are so obviously unhappy with being home (I'm not too happy about it either but at least no one will see our meltdowns); they still won't get dressed, but are instead playing at the train table. Together. A recipe for disaster today. I've come upstairs to hide and regroup. Ugh, here they come. Wish me luck. It's going to be a long day.