Help me i dont know what to do with my eye!!!?

Ok so like, when i was working the other night, there was a spot in front of my eye - you know when youlook into a bright light and an imprint is left there? ok well what happens is that it just appears - and i dont look into any light. then it gets bigger until i cannot see out of my right eye. Then about an hour or two later it starts to fade until my sight comes good again. It happend again today but this time i started to feel terribly sick in my stomach. Whats happening to me? What could it be?