I'm feeling extremely dizzy at night. If I don't go to bed immediately I start feeling nauseous. Wake up feeling better but still a little nauseated.

Many causes. There are many possible causes of your symptoms. Check pregnancy test. Labyrinthitis (Vestibular neuritis) is a syndrome of feeling dizzy, like the world is spinning, with nausea, worse with movement and usually somewhat relieved by holding still.. See your doctor for an evaluation if not better in 2-3 days.