My chest or lung on the left hurts when i breathe, also sometimes i rub on it i can feel the pain?

For some reason, i sometimes suddenly have a blocked nose, and its hard to breathe. sometimes when i breathe the left side of my chest/lung hurts. also when i rub on it, it also hurts.

why is it happening anything to resolve except for seeing a doctor?
this has happened propb like a month now!

Lung Cancer