I have had a very similar experience for about 8 months now. Chronic feeling of having to clear my throat because it feels like I can't breathe well. I am able to hack up whitish-clear, foamy mucus, but it seems there is an endless stream of it, that I cannot get rid of. It is magnitudes worse after eating/drinking. Occasionally, small amounts of cottage cheese like stuff will come out, but mostly the sticky, clear to white-foamy stuff that feels like it coats my throat and blocks my airway. It is very annoying.