Polar Bear Breaths

A therapist once told us about "Polar Bear Breaths": deep breathing to help during stressful situations. It's something we try to remind our daughters to do, especially when a meltdown is seconds away. See, polar bears apparently know this instinctively - to breathe a lung-full of fresh air after awaking from being tranquilized and tagged (understandably stressful): they wake up, shake their bodies, and then take several slow deep breaths.
These past few days, since arriving home from Africa with two toddlers, each of whom have plenty of "adjustments" to work through - Ruby has reminded me frequently, and each of her brothers, to "take a Polar Bear breath". There have been moments - no there have been many many times, in which I have had no less than two (and often three) kids vying for my lap - hitting each other, pushing, whimpering. There have been many many times in which I have had one on my hip while screaming, one hanging on my leg while crying, and one calling "Momma!" from the other room...all while I am trying to unload the dishwasher, or decide if I should answer the ringing phone...
You know that feeling in your lower back? that twinge that threatens that your back is about to go out? I've got it. Dave keeps warning me not to carry both boys at the same time while going up and down the steps in our house. I know he's right. But sometimes the physical work of carrying them seems more bearable than the emotional work of dealing with the crying/screaming. Not to mention the guilt of knowing I am not currently able to meet any one kid's needs to level I want, much less all four kids.
I'm trying to figure out how much of the boys' emotional state is related to their age (almost two), and how much is related to their adjustment into a new family, and how much of it is because of their very traumatic pasts (and their need for reasuarance and security), and how much is just jet-lag... and can I ever let them "cry it out" when they are having a tantrum? and can I flick their hand when they hurt me or their sisters? or will it damage their little hearts even further?
And I'm wondering if I'll ever have the energy to finish unpacking, and I'm considering allowing our Christmas decorations to be our new motif so I don't have to fuss with putting all that stuff away only to take it back out a mere 11 months from now...
Have you noticed I'm a wreck? =-) It's like post-partum stuff or something.
Time to breathe like a polar bear.