I forgot to warn you about taking anything that is drying to your lungs. That just turns the mucus to glue.
Take a large daily dose of vitamin B5 (about 500 mg.). There are no side effects. Then you can add other natural anti-inflammatories. Vitamin C is good. So is mullein extract. N-acetyl-cisteine is another. There are lots. Check on the internet. I take a few, but my mainstay is B5.
I found out that dairy was causing almost all of my muscous build-up and once that was completely cut out, it decreased a lot.
Omega 3 at high doses also has helped (4.5g with 750/500 of EPA and DHA) but not as a liquid which I have just found out because it is giving me huge reflux and increasing the muscous again (which the gel caps didn't do at all).
Keep your liquid intake high and avoid using anything that dries out your secretions if possible (ie. antihistamines).
Get a humidifier and sleep with it on.... i have the same thing but i had a throat infection so mucus is built up in my throat so im waiting for it to clear up