Why do I sneeze every morning when I wake and, in the night, when I wake?

This may suggest that you are sensitive to something in the environment in which you sleep. There are lots of possibilities here and it may take time to work out the exact cause, however, some common triggers include animal dander, dust and mould. Also, the likes of a strong candle, air fresheners, diffusers and even cleaning products may trigger the kind of symptoms you describe because they contain quite a few chemicals. You could try eliminating these things from the bedroom one at a time to see if your symptoms improve.