You are indeed suffering from allergy. I was suspecting that sneezing is due to a common cold, cause these both conditions share almost same symptoms.
But, having additional symptoms like nose itchiness, watery eyes characteristic just for allergy, means you have a case of allergy rhinitis.
Many varieties of lung problems can cause chest pain, including disorders of the airways such as asthma or bronchitis, infection of the lungs (pneumonia), and inflammation of the lining of the lungs (pleuritis, or pleurisy).
Chest pain that appears each time a person inhales, and nearly disappears with exhalation, is characteristic for pleurisy (an inflammation of the pleura, the lining of the pleural cavity surrounding the lungs, usually due to viral infection)
Are you experiencing shortness of breath and wheezing, too?