Oh my!! That was the single most stressful time in my life.
Things that helped:
I kept baby elevated - I bought one of those nap nanny things - so he would be at an incline, I also tried the swing, but he hated that. Plus being so little he was swaddled. I let him sleep on my chest a ton.
When he started sounding raspy/snotty, I would do 2 drops of saline in his nose... then suck. I read that sucking w/out the saline just inflames the tissue even more. I also ready not to suck if you don't see anything.
He never had more than a little fever, which was great. He dropped off on his eating. I took him into the pediatrician to get things checked - because I was having to pump to relieve the pressure of what he wouldn't eat... so I knew he was just feeling gross.
She said he was fine and told me to count wet diapers and if it dropped off in the next few days to come back in. He had also vomited a couple times - all of it was mostly green (snot) she said if it was any other color besides milk looking, snot, to come back in.
He still wasn't eating well so we went in and had them basically suck out the snot in his throat - the cold wasn't in his lungs. But there was enough goo down in his throat - basically it is a neti pot for your throat, the Dr. did this - it was horrific. I knew it was only saline solution.. but he screamed the entire time. I knew he needed it. That seemed to help him a ton!
It took a good two weeks to get over the cold.
I also put Vick's on my breast when he nursed - not right beside him, but near him so he could breath in the Vick's but, not get a strong dose of it.
Warm mist showers.
Make sure you stay hydrated, have some extra help. That really was one of the most stressful times. Sick newborns are the worst.
But he was tiny, and did fine!!