Ive been dealing with really thick mucus stuck at the back of my throat for over a year now, and its so hard to clear. Ive had an echo, ECG, chest x-ray, and even endoscopy and colonoscopy, but everything came back normal. The mucus just wont go away, and even inhalers only give me relief for a few minutes. When it gets stuck, I feel chest heaviness and trouble breathing, but my PFT results are normal. Ive had mild bronchitis since birth, but now one doctor is suspecting cystic fibrosis, though he thinks its unlikely. What could be causing this? Ive attached pictures of the mucus Im talking about.

.consult a pulmonologist for the same at the earliest