Late-night conversation that made my heart stop

I checked on Ro three or four times after bedtime last night, like I always do, and she was awake each time. I always kiss her, rub her little back, and ask why she's still awake and never get an answer. Until last night.

Me: Rosie, why are you still awake?
Ro: I no want to get in my bed.
Me: Why not Rosie?
Ro: I no want to take a long nap.
Me: Why not sweetheart? It's nighttime, you can go to sleep now.
Ro: No. I no want to sleep. Because... because.. because... I scared you leave me.

I can't even describe how it felt to hear those words. My stomach twisted and I still feel sick. Has she been lying awake every night worrying? Is that why she doesn't fall asleep easily lately? She's never said anything like this before, has never even mentioned a fleeting worry. I can't untangle my thoughts enough to figure out how long it's been going on. I'm not trying to oversimplify this, believe me I'm not, but I'm guessing it was at least partially triggered by TubaDad going on 4 business trips in the last 5 weeks and how we (mis)handled his being gone.

We tried to downplay it and just get through it and I think little Ro ended up drawing her own frightening conclusions. I feel awful about it. We should have treated it like any other big-deal situation with the girls -- lots of discussion beforehand, plenty of pretend play about it, maybe getting the girls to help pack his suitcase, taking them to see him off at the airplane, looking on a map to see where he was each night, that kind of thing.

Starting today both TubaDad and I are reassuring Ro and Ree every single time they go to bed that we'll both be here all night and in the morning when they wake up. And when TubaDad has to travel, we'll prep them WAY in advance and explain exactly what's going to happen. I'm buying a big wall calendar and we'll do a fun, lighthearted daily review of it over breakfast so they can see what's happening that day and what's happening tomorrow. Those are the simple first steps that we'll do -- we'll be doing these things and many more. We should have been doing them already. If you have any other suggestions of things that have worked with your toddlers and your spouse's business travel, would you please share? And please be kind in your comments -- I'm beating myself up enough for everyone.