Why am i feeling Dizzy and like im in a dream?

When i went to Horse of the year show in 2010 i felt like i was in a dream, i felt disoriented, Dizzy and very confused. I thought i was because of the crowd so i sat in the stadium where it was quiet and i began to feel better. The other day i was walking to class and it happened again, although i felt nervous and once i sat down in class it went again, this also happened yesterday when i was in New look with my family. I have no idea why this is happening. Also when i stand up or move into another room my eyes go really funny... Any ideas why this is happening and how i can stop it?