Thanks for your question on Health Care Magic.
I can understand your situation and problem.
Yes, this can be
bronchitis.
Your symptoms like cough, greenish phlegm,
chest tightness etc are seen in bronchitis.
You are also having exposure with
sinusitis and
ear infection patients.
So this can transmit infection in you.
So possibility of bronchitis is more in your case.
Consult pulmonologist and get done clinical examination of respiratory system and PFT (Pulmonary Function Test).
PFT is needed for the diagnosis of bronchitis. It will also tell you about severity of the disease. And treatment of bronchitis is based on severity only.
You may need inhaled bronchodilators, inhaled corticosteroid and antibiotic drugs.
So better to first diagnose yourself and then start appropriate treatment.
Hope I have solved your query.
Wish you good health. Thanks.