Why am I experiencing 16 or more chronic headache days a month

You most likely have a chronic migraine. The best way to figure out why is to see a doctor and he/she can depict why that is happening.

Smoking damages the respiratory system by inhalation of a foreign substance, that is absorbed and residue is left behind on our lungs sponge like substance. the gas that is inhaled also increase your blood pressure and dilates your blood vessels. also the process of inhaling and exhaling the smoke it causes irritation to the throat and mouth. smoking can cause lung cancer and other respiratory and circulatory diseases. 

The answer i think would be diet coke