Update your DOMAIN site.
Put this in your wp-config.php file
define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');
Probably thats fix your problem.
Wherever, you can revert back to the Default Theme, renaming the folder of your current theme in /wp-content/themes/ directory.
Trying too deleting your .htaccess file
Regards.