What's the Best Treatment for My Chest Pain?

Question

I have been getting a pain in my chest that is in the plural lining or in the bronchial area. This has been going on for the past 8 weeks. It usually occurs in the mornings and the pattern is in the form of crampy type waves. Usually, there are about 4-8 spasms that usually last from 1-1 ½ minutes. The pain that follows can be bearable, but not always; sometimes, it can be moderate to extremely painful.
What I usually do is take Flow Vent which clears the mucus of the chest and eventually reduces the pain. Usually for the rest of the day, I’m fine. Only once or twice has this pain occurred in the evenings. The pain is not necessarily caused by strain; it has occurred while I’m resting also. So, I haven’t been able to identify the trigger yet.
Will someone explain the cause and the mode of treatment for this illness that I have?