SOLVED:
I don't really know what happened, but there was problem in config.php - missing port num., and different PREFIX-ies in:
$db_prefix = "fusion1111_";
define("DB_PREFIX", "fusion1111_"
;
define("COOKIE_PREFIX", "fusion2222_"
;
Anyway, after logged into phpMyAdmin (via adminer.php - because I can't log-in ordinary way, because some kind of wrong certificate), I saw a lot of unnecessary tables with more then 2 prefix...
Edit Config.php to 1 PREFIX,
check & reset main settings in phpMyAdmin,
delete all unnecessary tables
Everything's done, everything Works.
Thanks for your time guys