Hi, Starting Yesterday My Throat Began To Become Scratchy And

Hi, starting yesterday my throat began to become scratchy and painful, and my nose congested. Prior to this I had no cold or cold like symptoms so this happened suddenly. When I lay down it feels like mucus collects at the back of my throat and it woke me out of my sleep. It became hard to breathe and I felt nauseated. When I stand up I fell much better but the scratchy feeling is still there. I've tried gargling in salt water twice, allergy pills, and decongestion medicine, but I can't sleep and this has become annoying. Thanks.