Considering the history of your illness it looks like bronchitis. It is not possible that these symptoms were caused by the gastritis. To prevent pneumonia you have to consult a doctor as soon as possible.
It is necessary to implement a medical examination with the care of a good doctor. Such nodules may, but need not be, onset of lung cancer. I wish you good health :)
Probably this is sn issue connected with paranasal sinuses. You will have to go to the laryngologist for some antibiotics.