Thanks for your question on Healthcare Magic.
I can understand your concern.
I also feel that you are having acute exacerbation of asthma.
Normal chest x ray rules out pneumonia or lung cancer or other lung diseases.
Chronic cough, congestion, phlegm, wheezing,
shortness of breath etc in asthmatic patient is suggestive of acute worsening of asthma more.
So get done PFT (pulmonary function test).
PFT will tell you about severity of asthma and treatment is based on severity only.
You may need long acting inhaled
bronchodilator (formoterol or salmeterol) and inhaled
corticosteroids (ICS) (budesonide or fluticasone).
Oral combination of antihistamine (levocetrizine or
fexofenadine) and anti allergic (montelukast) is also beneficial in your case.
Don't worry, you will be alright with all these.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.