What Causes Difficulty In Breathing Followed By Excessive Sweating?

My son is 13 months old. Around 2 months ago, he started showing signs of obstructed breathing. He snores in the night and during the day, he breaths through the mouth especially when he is playing. he has refused to take semi solid food of thick consistency; only feeding on somewhat watery cereals. he sweats abnormally especially when active and during sleeping. He is very active but very small for his age. Currently weighs 9.2kg. the doctor said he has swollen adenoids and referred him to an ENT doctor. kindly advise please