This is most likely nocturnal dyspnoea.
You didn't state if you were asthmatic, because it is a major cause. If you happen to eat something you are allergic to, almost every night before going to bed, then you are most likely to experience shortness of breath.
I would strongly advise you to closely watch what you eat, and note the days you do have difficulty breathing and what you have eaten. I read recently that some people do develop an allergic reaction against cranberries, especially around the age of 21.
Other causes include
Sleep apnea, which is difficulty sleeping
Anxiety is another great culprit.
Take care.
I would definitely see a doctor soon about this. Chest pain with coughing are nothing to play around with. You could have bronchitis, I really don't know, but, I do think you should get this taken care of soon, it is better to be safe than sorry.