Suggest Treatment For Recurrent Nasal Congestion

Hi, My son is a year and two weeks old. He is always having nasal congestion and most times breathes through the mouth because his nose seems blocked. When he sleeps, I see some foam coming out of his mouth and sometimes I can hear him snoring. Sometimes he s fine and plays around very well, while other times he s cranky and unusually quiet. Meal times are also an issue as he struggles and most times pukes his food. Because of this, we still make his food watery so that it can have easy passage through cos he hardly closes his mouth to swallow and most times we force him to eat. I can t wean him yet as breastmilk is what he feeds on the most. I have given him multivitamins and antibiotics, yet nothing. The nasal congestion keeps coming back and he s not eating freely as he should at this age. Please help me with a solution for him.