Have you tried the nasal spray Azalastine…..it is the gold standard for nasal dripping, coughing and mucus build-up. If I forget to take it in the morning I start coughing from the mucus in my throat and getting a runny nose most likely from allergies. Before bed I take Mometasone. It is a corticosteroid but my ENT doctor told me it doesn’t cross over into the blood stream but stays in the nasal area which means you can take it forever. Another gold standard! I also take Famotadine for reflux. Works semi well.