I too am an OB zebra, like Katinka and Caspiana, diagnosed in February this year. I'm so sorry you are coughing badly, its horrible isn't it?
It would seem that this disease affects us all differently sometimes, I guess that's true of every condition though, for myself, yes I do sometimes cough, not often but when I do it is so irritating!
It feels like the mucus is stuck in a dead end and just shifts around, trying to find a way out, eventually it comes up but I have learned how to speed it up on its journey. I use the breathing excersises from the British Thoracic Association, the ones about huffing, basically, instead of coughing hard and hurting or straining, you push Sharp breaths out from the base of your tummy , empty your lungs as far as you can, I can feel the gunk move when I do this, and eventually it finds its way up far enough to get rid of.
I would have to say here that I do have mild Bronchiectasis as well, and that causes some mucus and complicates infections.
Do stay in touch, and I hope this has been helpful. As already said, we are a rare breed and have to stick together!