What Causes Cough With Phlegm And Mucus, Chest Pain, Heaviness, Acid Reflux?

Hi, for almost three months already, i am suffering from a cough-like ailment. But it is not as frequent as the regular cough, nor does it feel like one. It is just that I sometimes produce phlegm or mucus. I also noticed three months ago that when i drink cold water or any icy beverage, i feel a sharp chest pain. Sometimes, i feel that I have a clogged nose, but it is now more frequent than before and that my chest feels a bit heavier now. I have not consulted a physician yet. 3 years ago I was diagnosed with ulcer in the diaphragm, but it was complete healed after taking medications. I also have heartburn at times. Will you please tell me what could be happening inside me? I fear that it would turn out to be cancer.