Thanks for your question on Healthcare Magic.
I can understand your concern.
By your history and description, possibility of
musculoskeletal pain is more likely because of sleeping on that side.
But since you were a smoker, we should definitely rule out lung pathology like
bronchitis for your burning.
So when you consult your pulmonologist, ask him to check for
1. Clinical examination of respiratory system
2. PFT (pulmonary function test).
PFT will tell you if you are having bronchitis or not.
If PFT is normal then no need to worry for bronchitis.
Musculoskeletal pain is more likely in your case.
So avoid bad postures in sleep. Take painkiller like
ibuprofen.
Don't worry, you will be alright.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.