Hello, The cause of chest pain could be anxiety, and also the fact that smoking causes constriction of blood vessels by lowering nitric oxide levels. That can lead to spasm like chest pain in smokers. Since you have quite smoking a while ago, it may take few weeks for the blood vessels to resume their normal functioning status. In addition, for anxiety I would suggest you to consult a psychiatrist. They will help deal with anxiety better, by using medications and/or counseling therapy. The neck pain can also be caused by stress and anxiety; use warm compress and relaxing hot baths for relief. Avoid excess caffeine as that can all cause chest pain and racing heart beat. Moreover, for the complaints of fatigue you may use vitamin supplement like Centrum or Berroca as the symptoms may be caused by low levels of B-complex vitamins. Try to eat healthy balanced diet, and if the symptoms does not improve or worsen visit an ER to get ECG. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr Ayesha Shareef, General & Family Physician