After furaffinity reset all of the passwords on the site I was unable to log in because this account is apparently not associated with the email address I would have used at the time of its creation. I had created another account to replace it, and posted a comment, saying that I would no longer be using this account.

Thanks to Dragoneer I was able to get back on to my account, and I have disabled the other one. I'll be keeping that other account as a backup in case something like this happens again.