Keep him elevated.
When there is mucus and congestion and sinus drainage etc., it gets worse at night because the person is lying down. Hence, the mucus still drains down the sinus and throat and accumulates in the throat... causing the cough reflex, hence causing coughing. And or gagging.
A baby, cannot clear, their throat nor spit it out.
Hence, discomfort and more coughing and/or gagging.
Keep him elevated.
You can, under his crib mattress, put a pillow there to elevate the mattress.
Don't put a pillow under his head, because this is a safety hazard.
Did you take him to the Doctor?
If not, do so.
To make sure, he is fine.
Congestion/mucus/coughing, originates from:
1) the chest, or
2) the Sinus.
Where is his congestion originating from????
If it is his chest, and being he is so young, you need to make sure he does not get Pneumonia or something.
Lungs in babies, are sensitive.
Even a sinus infection, is not good... and the dripping of mucus down the throat can infect the lungs too, causing a secondary infection in the lungs.
Hence causing Bronchitis or Pneumonia.
I know, that happened to me, just from a Head cold.
Take your baby to the Doctor.
Watch for any worsening symptoms/fever etc.
Orange juice, makes mucus worse.
Keep him hydrated.
Using a bulb syringe/suction in his nose, if you use it too much... it can abrade the inner nose and cause pain. So don't use it too much.
Or, there is something called "Little Noses" which is a nasal decongestant drops, for kids. Which breaks up nasal congestion. Find it at drug stores. I have that for my kids.
When babies are sick like this, you need to wake up and check on them. They don't get sleep, nor you.
It is temporary. He is sick. So just make sure he is comfortable and can breathe..... take him to the Doctor and monitor his symptoms.
Or as a last resort... hold him on you while you are sitting in a chair, and let him sleep that way. He is upright in that position, and it may help with the congestion and coughing as the mucus drips down his throat.
Even with a chest cold/congestion.... being flat on your back, makes it harder for the lungs and causes coughing. Because the mucus accumulates and pools.
good luck,
Susan