Thank you for your consult at DoctorSpring.com.
From how long have you been symptomatic? any variation in symptoms based on day / night time, precipitated by smoke, dust, at home/ outside home, any specific day in the week? what is your smoking status?
from what i understand is you have no fever, mucoid sputum and mild breathing difficulty.any aggravating or relieving factors for your breathlessness? is there any restrictions/ limitations in your daily activities?
I also understand that the CBC, and echo are normal.
What i would suggest -
To make matters more clear, kindly provide status of smoking, any allergic symptoms for you or any first degree relatives, duration of symptoms with precipitating factors.
Possibilities - Allergic, GERD, and infective.
Work up needed - do a sputum examination - gram stain, stain for fungus, and mycobacteria, Chest x ray. these are all cheap but very much informative investigations. you can easily rule out / confirm an infection/ allergic process from sputum microscopy and staining.
Suggestions - deep breathing exercises - similar to yoga( dr. Google might give demonstrations / illustrations for it) early morning for half an hour usually helps to relieve you of the phelgm. continue GERD medicines, quit smoking -if you smoke, and consider some anti allergic medications like Xyzal 5 mg and singulair 10 mg at bed time.
If most docs you already seen assured you that you are ok, may be you are ok and what you are experiencing will just be an exagerated normalcy. you can clear the doubts by seeing a pulmonologist - who will also require the same pieces of info i sought, along with a chest x ray.
Hope this helped, please feel free to discuss further. Wishing you a speedy recovery
Dr. Jacob George P