40 y old female, woke w vertigo attack, still very dizzy, worse when lying down but present moderately at all times. no other sym's. er or wait n see?

Likely labyrinthitis: Labyrinthitis is the most common cause of vertigo. Typically, it comes on suddenly (sometimes after a viral illness). The symptoms may last minutes to several hours, often accompanied by nausea--interspersed by periods of feeling well. It may become worse over several weeks, and then will gradually resolve. The symptoms may be incapacitating, so not a good idea to drive. See Comment.