What Causes Tunnel Vision, Inability To Focus And Dizziness?

Hi. Tonight, while watching a movie in a theater, I had a sudden episode of tunnel vision, inability to focus, and the feeling like I was going to faint and vomit. I quickly left the theater to find the bathroom, but was unsteady and swerving, bumping into things and not being able to see clearly. I was disoriented, trying to find the bathroom and had to be guided by an employee. I was in a hurried panic as I didn t want to vomit on the floor. Once in the bathroom, I knelt at the toilet but didn t need to vomit and instead had the urge for a bowel movement. During which, I was breathing in short, rapid breaths, felt a rush of heat all over my body and broke out in a cold sweat. After a few minutes, I was able to stand up, still feeling a bit unsteady, and I also felt shaky. I washed my hands, went out to the lobby and asked for a cup of water. I sat down for a few minutes and soon returned to normal. I had a headache for a brief time afterward, but that went away too. It was very scary and I have never experienced anything like it before...although, it was as if I had become instantaneously extremely drunk and then back to sober within the space of about 15 minutes. Any ideas?