First, make sure you've tried logging in with both your e-mail and your account name. Either login credential will give you access to your account.
If that doesn't work, we recommend trying again in a little while. When the server experiences momentary issues, attempting to login may result in errors that imply your account is missing. Rest assured that your account will be there waiting for you once everything is up and running as normal!
If you've tried both of these and still cannot login to your account, please contact us with your Account Name and your Account E-mail, and we'll help you out!