What Causes Dizziness, Shortness Of Breath, Chest Tightness And Blurred Vision?

50 year old male, was exposed to raw diesel fuel exhaust at the beginning of august. smoker 35 years. over weight. got a dry cough that came on suddenly which causes dizziness, shortness of breath, chest tightness, blurred vision which last for about 1 min than goes away. there feels like there s a tickle which triggers the cough. physical activity, cold air triggers cough fainted once at breathing test. redid breathing test about 2 months later was told have a breathing rate of 80%. did stress test 2 day(treadmill and next day at rest) was told heart is good. x-rays are showing they are clear. blood works coming back normal. some days don t have to many coughing fits, other days they is numerous. taking 3 puffer they do not seem to be helping feel like its causing heaviness of the chest more. what could be causing this? its been going on for for atleast 2 and 1/2 months and the docter has no answers for me