What Causes Vertigo With Severe Sweating?

Hello. I suffer from extreme vertigo every 18 months or so. The symptoms that present are somewhat similar to a stroke in that there is numbness in the extremities, severe sweating, but also vomiting that goes on for hours until I get to an emergency room. Can't control the dizziness or vomiting even if I keep my eyes closed.
Can you tell me what causes this and if there is anything that I can do to avoid having to take an ambulance to an ER?