Thanks for your question on Healthcare Magic.
I can understand your concern.
No, I don't think these symptoms are due to Stills disease.
In my opinion, we should rule out lung related diseases like bronchitis and
lung infection in your case because both these can cause breathlessness and
chronic cough.
So
consult pulmonologist and get done clinical examination of respiratory system, chest x ray and PFT (Pulmonary Function Test).
Yoi may need antibiotics, inhaled bronchodilators (formoterol or
salmeterol) and inhaled corticosteroid (ICS) (budesonide or
fluticasone) depending on the basis of reports.
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.