UPDATE#1
in my-sites.php i found this:
require_once( ‘./admin.php’ );
if ( !is_multisite() )
wp_die( __( ‘Multisite support is not enabled.’ ) );
if ( ! current_user_can(‘read’) )
wp_die( __( ‘You do not have sufficient permissions to view this page.’ ) );
can I change it in some way? or in admin.php? Then I could turn multisites off and still be able to access my dashboard or admin pages?