Chest tightness and discomfort, with no cough?

I've been smokin for like 8 years and stopped last year when the chest pain started, so now i only get those symptomes when i smoke even 1 ciggarette alone will have me feelin the chest tightness and discomfort, but with no cough at all even when i force my self to cough its not even productive, the chest pain feels like more located at the wall and ribs in the lower part of my lungs, feels like an obstruction by small particles am not sure, another thing is that i feel really relieved when i do exercises like it cleans my lungs, even without coughing , plus i had alot of episodes of gastritis and heartburn when i was young but it has been treated like 2 years ago, so am really confused since the pain only comes after smoking but there is No cough!! Any help would be really appreciated .