void OnSceneLoaded(Scene scene, LoadSceneMode mode)
 {
     if (startingSceneIndex != SceneManager.GetActiveScene().buildIndex)
     {
         instance = null;
         SceneManager.sceneLoaded -= OnSceneLoaded;
         Destroy(gameObject);
     }
 }
 void Start()
 {
     if (!instance)
     {
         instance = this;
         SceneManager.sceneLoaded += OnSceneLoaded;
         startingSceneIndex        = SceneManager.GetActiveScene().buildIndex;
         DontDestroyOnLoad(gameObject);
     }
     else if (instance != this)
     {
         Destroy(gameObject);
     }
 }