Can't login in Icecrown

It started yesterday, I can't somehow use my account in Icecrown. I keep getting disconnected after a few seconds, can't logout, can't use any skills and items, all I can do is move. Then when I try to login again after being disconnected from the server a "a character with that name already exists" message appears. After a few minutes I can login again but gets disconnected after a few seconds. The cycle continues, it's like this since yesterday. I tried to delete the cache folder and the logs folder, tried to remove my addons, changed the realmlist in the config but nothing's working.

please help >.<

P.S. sorry if there are mistakes in my english, it's not my native language.

UPDATE: I tried to make a new character in Icecrown, it works and I'm not getting disconnected. The problem only persists on my old characters.