200mg is a "typical" dose for someone who has done MDMA a few times, it's a tiiny bit high for someone who's never taken it before, but even so, most people probably take around that amount their first time. It does seem really strange that this happened :/
Unless you have literally no health care coverage and 100% can't afford to go, I really recommend going and getting tested for a seizure disorder. Or at the very least: Bring it up to your doctor next time you see him/her. Unless it just happened that day or the day before, it would be better to see your family doc than the ER doc. It's always best to be honest, they can't do anything to you legally. Even if you just tell him/her what happened without releasing the MDMA details, they may discover an underlying condition. Until then, if you do decide to roll again (not a great idea, but if you do), do so at home with a trusted friend, and have a friend around the entire next day to watch you. If it happens again the night of or the day after, head straight for the ER so they can do their tests while the effects on your brain are still present.
Be careful about overheating, as that is often what causes seizures when people are on M. If you were out raving the night before, that would be my best guess as to the cause of the seizure. If that's the case, save your rolling nights for house parties or at home, where you won't be dancing like crazy. Your body has a hard time regulating your body temperature on M and it is made much worse when you're dancing. Some people are completely fine with dancing all night while high, but some bodies can't handle it as well.
And no, it was definitely not fainting. Your eyes would never be open and you would never be shaking!
