It's time to shut this thing down. There are a lot of pissed off members that are stuck between a rock and a hard place. On one hand they want to get their entries in so they can't give stop trying for fear that the competition will fill up. On the other hand this is a colossal waste of time and is just pissing people off.
Shut down the registration, figure out a new plan, and open it back up when you're ready to handle the scale so it's fair for everyone.