I'm really struggling with this thick mucus at the back of my throat that's been around for about a year now. It just won't clear up no matter what I try. I've had an echo, chest X-ray, endoscopy, and colonoscopy, and everything comes back normal. Even when I use inhalers, the relief only lasts a couple of minutes. Whenever this sticky mucus gets stuck, I feel chest heaviness and have trouble breathing, but my pulmonary function test results are normal. I've had mild bronchitis since I was a kid, and one of the local doctors mentioned it might be cystic fibrosis, but he also said that's pretty unlikely. What could be causing this? I'm attaching pictures of my phlegm too.

.consult a pulmonologist for the same at the earliest