I had the same issue a few months back I tried this and this works for me.
define('FORCE_SSL_LOGIN', false);
define('FORCE_SSL_ADMIN', false);
define( 'CONCATENATE_SCRIPTS', false );
define( 'SCRIPT_DEBUG', true );
try to load wp-admin with SSL.
After reloading it looks OK, maybe after re-login, set SCRIPT_DEBUG to false.
hope this help