I'm kind of with mama_tigress: I just wanted to let them do what they needed to do so that I could get my girls home. Um, what to add to all the excellent posts above . . .
-Remind yourself that your babies are where they need to be. The NICU was gut-wrenching at the time, but I was so grateful that it existed. And now that I have my almost-toddlers, these beautiful girls with their bright eyes and infectious giggles . . . I am even more grateful for the wonders of CPAP and artificial surfectant and all the rest of it. No, it's not how any baby should start. But my girls wouldn't be here without it. It's helpful to remind yourself why
you're doing this awfully hard thing: it's so your babies will live.
-Expect setbacks. Expect weirdness.
-They're yours. They're yours even though they don't come home with you. You are being a loving mother, even though you'll feel like crap when you drive home from the hospital and leave them behind. You aren't crap, you are a loving mother who is seeing that her babies get the best possible care.
-As a fellow momo mom: do rest when you get home. It feels bad to say it, but after that long hospital stay and a c-section (normal momo protocol), the babies' NICU stay does have the benefit of letting you get a few weeks of full-night sleep (minus getting up to pump). Take advantage of it; it's the best thing you can do for your babies, because you will be ready to take care of them when they come home. It's okay to be relieved to be out of the hospital, even if your babies are still there. You can get their home all ready for them.
-In my experience (YMMV) getting breastfeeding started doesn't have to happen in the NICU. I tried nursing a bit in the NICU, but we didn't really work on it till they got home, and they didn't get it till a month after they got home. Pump like mad, of course, but don't freak out if your babies take awhile to learn to nurse. They're busy learning to breathe.
-Don't be afraid to ask the nurses questions. Our nurses were so great about letting us know we could call any time, even at night, just to ask how the girls were doing. We visited every day, but it was good to be able to call before bedtime, just to see how the little ones had settled in for the night, and to talk to the night shift nurse. Almost all the NICU nurses I met loved their job and loved the babies, and were more than willing to talk to us about our girls and about what to expect. They were wonderful. Ask lots of questions - or don't, if what you want to do is just to sit and cuddle with your babies.
-Sing to your babies. This is my most frivolous suggestion.
But I would run out of things to say, or I'd find that saying things like, "we all love you and can't wait for you to come home" would choke me up too much, but I wanted them to hear my voice while I was there, so I'd sing to them, just softly, while I held them. They still love to be sung to.
I don't know what the future has in store for you, but if it's any encouragement, I was where you are last year, and now we're all home, safe and sound. And they're the sweetest babies in the world. And you would never, never know that they had the rough start they did. They're attached and healthy and happy and loving and loved. God bless you. May you have the shortest possible NICU stay, and may it be entirely uneventful.