Almost Six-Month Old Fraternal Twin Boys: I Still Fear Change

My fraternal twin boys will be 6 months old in five days and I still hate change. You'd think I would have gotten over this about six months ago when my life turned upside down but, alas, I still ain't a fan.
My sons couldn't be more different. Baby B was the colicky cry-baby and Baby A was the I-put-myself-to-sleep angel who only cried when something was definitely wrong. I got used to this, I relied on this, I based my days around this and was beginning to think, "Hey, this isn't that bad." However, now it's upside down.
They were sleeping through the night long enough to take for granted, especially last night when Baby A started crying at midnight. My husband tapped me awake, as I wear ear plugs to drown out his snoring and sleep-talking, saying it was my turn because he consoled him an hour ago. What happened to my angel?
So, I consoled and offered a pacifier and a quick back rub before slipping back into bed. Amid crappy dreams (I never have pleasant dreams featuring dark chocolate dripping off Tom Hardy's chest ... sigh) my husband woke me at 4:30 a.m. to cries from the nursery -- sounds like the title of a mystery novel. He informed me he'd been up most of the night - not sure why he didn't wake me for our usual take-turn night parenting. Both boys ate as Baby A woke up Baby B with his screaming.
Who's this baby and what happened to my good boy?
This change may seem simple but these boys are my world as I am a stay-at-home mom. I'm their main caretaker and ... well ... this made me depressed. What if they get sick or start fussing and I need to figure out what's wrong? What if something is wrong and I mistake it for simply being fussy? What if? What if? What if? What if?
Finally today, after feeding Baby A and watching him fall asleep in my arms, I thought, "You know what?! There's nothing I can do so I need to embrace the chaos. Embrace the change." There's nothing else I can do except try my best, know my limitations, remember I'm not supermom because there is no supermom and these boys need me. Also, remember to breathe!