Don’t panic. You can still access your website with the safe URL
This link appears in the plugin’s settings page and you should receive it by email too
Don’t have the safe URL?
Rename the plugin directory /wp-content/plugins/hide-my-wp to /wp-content/plugins/hide-my-wp1 so that the plugins wouldn’t hide the wp-admin and wp-login paths. Save it and all the plugin’s settings will roll back to Default mode.
Login using http://example.com/wp-login.php and you can rename the plugin back to /wp-content/plugins/hide-my-wp and continue the setup.
Make sure you remember the secure parameter, and it will be much simpler.