I don’t think you’ve understood properly. I can’t access anymore the old account albatrospalestra.it with my old password, after I have changed the host name.
The new url does not exist (chonkwontaekwondoacademy.it).
To recover the password I can go to login/wordpress.org, insert the User ID Albatros and then click forgotten password. In this case I am prompted to enter an email address. If I put there my email address I am prompted with a “user not existing in wordpress” message.
On the other hand, if I go to http://yoursite.com/wordpress/wp-login.php, that is to http://albatrospalestra.it/wordpress/wp-login.php, I am readdressed to chonkwontaekwondoacademy.it, that is followed by a internet error because that website does not exist. I haven’t registered nor hosted that site.
I cannot use any of the suggestions you gave me. I’m only sure the account Albatros is still somewhere in both wordpress.com and .org. So I hope an admin could help me.