After a specified amount of time, in which the account was not used, (18 months of inactivity, I believe, but I could be wrong) the account could have been deleted. Since many, many accounts are created on Feral-heart, this "clearing out" is a way to keep things more organized. This could be the reason that your account was deleted. If that's the case, your best option would be to create a new account if so desired.
As for your messages, did you check the little "save a copy in my outbox" option? If you did, make sure that your message actually got through to the moderator. If you just type in the moderator's name in the recipient space, it might not go through, since multiple people may have the same nickname on the forum. Your best option would be to visit the Staff List, click on the moderator's profile, and send the message, or just click the link to message them from the Staff page.
Hope this cleared some things up for you. c: