I am a 12 year old ,and I think I

Patient: I am a 12 year old ,and I think I had a cold. It did not come with a fever, but instead with a cough and a sore throat. Today is the fourth or fifth day of it, and my sore throat disappeared completely. Unfortunately it was replaced by a burning sensation in the left side of my chest every time I inhale. My cough also is going away ,but the chest discomfort is still there. In addition, my left ear feels very full. I am also going on a long flight in 5 days and am not sure what to do. Can you please help me?