Taking into consideration your height, weight and your profession, and the high percentage of alcohol and tobacco abuse in your peer group, I would first think of the possibility of Hypertension and associated problems including of the heart. Please see a physician and get yourself examined. Please do regular exercise and also try to reduce your weight. Meditation and Pranayama on a regular basis would certainly help you in the long run. After your consultation with the physician, you might benefit seeing a psychiatrist also. He might give you tips on stress management.