Thanks for your question on Health Care Magic.
I can understand your concern.
Your initial symptoms are suggestive viral upper
respiratory tract infection (URTI).
But your current symptoms of fever,
chest pain, breathing difficulty, lethargy etc are more suggestive of either
lung infection (
pneumonia) or
bronchitis.
Both (pneumonia and bronchitis) are common after viral URTI.
So better to get done chest x ray and PFT (Pulmonary Function Test).
Chest x ray is needed to rule out pneumonia.
PFT is must for the diagnosis of bronchitis.
On the basis of these reports, you will need antibiotics, inhaled bronchodilators and inhaled corticosteroid (ICS).
So first diagnose yourself and then start appropriate treatment.
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.