Humidifier works really good with cold
Take him to the er. My son got pneumonia. At early age. he would barely eat. Cried alot. Couldnt breathe well. Coughed. And his chest compressed when he would breathe. Better safe the sorry.
If his only 10 days old you might want to take him to the hospital. is he wheezing at all? Shortness of breath. Watch his chest and stomach area and she if it looks like his sucking in and his chest caves down. If so you need to take him immediatly very chesty can mean a couple differnt things bronchitis or a chest cold or several other things but just watch his breathing and make sure he gets plenty of fluids so he doesnt get dehydrated
Saline nose drops and that nasal suction bulb. Run a humidifier. Also steam up the bathroom and sit in there. As long as there's no fever that's about it. Good luck hope feels better soon