I don't smoke but my wife used to but quit when she fell pregnant with our daughter, she has never felt better since, as your showing all these symptoms I would go have a check up immediately, and stop smoking prompt, I have no idea
what the nicotine craving is like but if it came down to my health then im sure I would find away, My father smoked like a trooper and had the horrible cough for years, then he developed chest pains and he had got Angina but he was a large bloke aswell so his weight will have contributed to it some what.
He had a heart attack and died and looking back afterwords there where signs that I failed to recognise, these where he started smoking menthol cigarettes and he kept stopping for rests as he was short of breath, I don't want to panic you im just stating facts in my fathers case but in reality you should deffinatley go have a check up or chest xray .