We're having trouble breathing. After taking medicine, we started gett…

We're having trouble breathing. After taking medicine, we started getting a runny nose, the nose is clear, but mucus sometimes gets stuck between the nose and throat and we cough it up. And when we suck on the chest, thick mucus comes out. What can I put in my eyes? The pediatrician said that he was lying down in his stomach then swallowed water, now it comes out. In my opinion, this is just a cold. There's no fever.