After I'm Asleep For Awhile I Get A Plug Of

After I'm asleep for awhile I get a plug of mucus in my throat. I try swallowing to make it move down my throat but it won't move. It cause me to snore, wakes me up, and the snoring keeps my husband awake. I believe I have allergies to many things here in the desert. I've been to my Doctor and we've tried two different antibiotics with no relief. Currently I am taking 24 hour Claritin in the morning every day (cannot take it at night it keeps me awake. Can you help me with my allergies and this plug of mucus at night?