Saline and a humidifier are your best friend for the congestion. My girl has been super congested the last week and the saline spray and keeping her humidifier on in her room have helped a lot. My girl had a cough like that too around the same age and I barely slept watching her on the monitor but she ended up being okay after about a week. With the vomiting just make sure he’s keeping up with fluids. If you’re breastfeeding, let baby have as much booby as they want and keep on eye on wet diapers to make sure they don’t become dehydrated. There’s no harm in calling the pediatrician tomorrow too if baby doesn’t seem to be feeling better. Best of luck! I hope your little one feels better soon!
My 16month has been the same way she is super congested, started coughing decently the last two days or so and this morning just vomited on her self twice from the coughing and mucus. I’d see if your pediatrician recommends any prescription allergy meds, using a humidifier at night and using a little bit of saline spray and a bulb syringe should help