Thanks for your question on Health Care Magic.
I can understand your concern.
Since your heart related reports are normal, no need to worry much for cardiac diseases.
Bronchitis can cause similar symptoms.
So better to
consult pulmonologist and get done clinical examination of respiratory system and PFT (Pulmonary Function Test).
PFT is must 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 antibiotics, inhaled bronchodilators and inhaled corticosteroid (ICS).
Don't worry, you will be alright.
First diagnose yourself and then start appropriate treatment.
Hope I have solved your query. Wish you good health. Thanks.