Mysterious Fainting Episodes

Hello, I'm 17 years old and I keep having an episode of fainting, that usually results in convulsions. This episode happened when I feel down a flight of stairs when I was helping someone stain a floor. I recall a warm sensation as the steps I fell down hit me, feeling like my limbs are moving around uncontrollably, being unable to move and hearing a few thoughts while a sort of ringing noise was happening. Since then it's happened 5 more times , nothing really related except the presents of chemicals on two and low potassium levels after two episodes. The other odd thing is I usually feel very nauseous right after and vomit at least once. My girlfriend had witnessed one was actually the first person to see such a thing. I feel like something brushes under my foot or I loose control of my balance, and then fall, can't move and then black out.

She reported " you started having a seizure BEFORE u hit the floor. then you hit the floor, your head started thumping back and forth, your eyes were blank, you were frozen, and your breathing was kind of shallow

then you foamed at the mouth, were shaking, then you got up and walked nowhere in particular "


Tests I've had
-3 EEG's
-1 EKG
-1 or 2 MRI's (I forget)

It's been a pain in the ass, doctor's aren't seeming to do ANYTHING about it. Truth be told, these "episodes" are getting more and more common. I just had it happen a 5th time, and the other four were at least close to a year apart. This was like 3-4 months the last time it happened.

What do you think this is ? Suggestions ? Please help

Note: Note : The EEG's have come up normal