when i do it, they say "login approved/ go back to previous site" and then "Error decrypting wallet, please check that your password is correct"
This is happening because that Authenticator has been expired and you used that already, if not you made another request for an email authentication.
Hello
i dont remember 12 words, how can i recover my account?
There's no way for you to recover that wallet, if there's no balance on that wallet you can just simply forget it and try to work for some other wallets. Create a new one and remember the paraphrases.