I woke up this morning with severe vertigo , and when I sat up in bed I felt severe nausea and had to run to the bathroom, followed by a sudden sweat that accompanied the nausea. the room is spinning and the vertigo does not go away even when my eyes are closed. The only time the nausea is lessened is when I lie down. once I sit, stand, or walk, the nausea becomes so unbearable that I have to immediately lie down again. 8 hours have passed since the vertigo started and I still feel the same. What is this sudden vertigo, nausea, sweating?