You wouldn't have to download everything again, just move everything to the FeralHeart folder again, really.
It might do the trick.
You might want to wait it out, or contact a staff member.
:c <3
Good luck!
Make sure you have the login page open before you open FH. After logging into the login page, wait a few seconds and then try to open FH and login. Sometimes it won't work the first time and will give you the "Failed to connect to front server error". If this happens, close FH (leave the login page open), and try to open FH again. I've sometimes had to restart FH 3 times, but it always ends up working.
The login page can be found here: http://feral-heart.com/login/index.php
Note: Make sure that when you're trying to login in-game, the login page isn't logging you out while you're trying to connect. This can be an issue with some users and I suggest trying a different browser and/or using a page refresher such as this one: http://www.refreshthis.com/