C.Ann glad to hear you aren't hurt too bad!
Do you have low blood pressure? I have extremely low blood pressure and I know exactly what that fainting feeling is like! I usually can get myself to the ground before I completely faint but I have had numerous spells:
1. Carrying my loaded lunch tray to the table on the first day of high school in the crowded cafeteria with WHITE jeans on. We had spaghetti for lunch. Splat! I was mortified.
2. Carrying a bowl of cereal into the living room on a Saturday morning to watch TV. I went down and the cereal was all over the wall.
3. Walking down the hall to the bathroom at my parents house. It was pretty dark. I crashed right through the drywall, but luckily didn't hit a stud or burst through the other side into my brothers room. I was so dazed I thought the cracks in the drywall was blood so I started screaming. My brothers finally decided to check on me. The thought I dropped a TV

Wouldn't that be reason enough to check on me? My dad wasn't happen about patching that very large hole!
AFter that incident I had a whole work up of tests done (EKG, blood tests, etc) and they concluded I just have low blood pressure. I took salt tablets for years and don't really watch my salt intake at all. I remember going in for my first visit to the OB when I was pregnant and the nurses were freaking out about my low blood pressure. They didn't believe it was normal for me until they called my regular doctor. At delivery my blood pressure actually was in the normal range and I was swelled like a balloon.
I have learned to get up slowly and sit as soon as I feel even slightly faint, but I still pass out from time to time. Hopefully this is just a one time thing for you!!!!