I can feel my heart flutter and I can't seem to breathe properly. Does this mean that I have poor lung health?

Not necesserily. Feeling your heart fluttering means that your hearts rhythm is not regular, most likely you are having some kind of atrial arrhythmia (ie atrial fib or flutter). This can be the reason for your respiratory problems rather than your lungs. It may also be a combination of heart and lung disease. You need to see your doctor, to diagnose the cause and discuss all your options for treatment.
You may have. It could be heart or lung or combinations or stress but it must be checked out. You must avoid tobacco smoke, caffeine and alcohol.