Help with DateTime functionality

Hello everyone. I'm going to have to steal a few minutes of your time (maybe even less) with a problem I have. Step to explain: I'm finishing out some themes of an arcade-type video game. The fact is that this game works through lives. Once you lose your lives, a progressive timer is activated (1, 2, 3, 4, .....) and when it reaches 15 minutes, the timer disappears and the lives return or, at least, that I would like it to do . The fact is that when activated it enters a kind of loop that produces the following. after 15 minutes, lives. If you spend an hour and twelve minutes, for example, the timer is still active, when it reaches an hour and 15 minutes, lives. That is, every time an hour passes since the timer is activated, the recovery loop is repeated, I do not know if I explain myself completely well. This is causing me a very intense headache because I do not know where to attack the script in question, which is this:

     DateTime time ;
     TimeSpan difference ;

     public Text text ;
     public GameObject notice ;
     public GameObject chrono;

     private void Awake()
     {
         if ( PlayerPrefs.GetInt( " LifeCount " ) == 0 )
         {
             Lives.Lives = PlayerPrefs.GetInt( " Life Counter" );
         }
     }

     void Start()
     {
         Time Manager();
     }

     // the save-class is called from the lives script when you run out of any

     public static void Save Time()
     {
         PlayerPrefs.SetString( "Time", DateTime.Now.ToString() );
     }

     private void Update()
     {
         print( difference );
         print( difference.Minutes );
     }

     public void TimeManager()
     {
         if ( Lives.Lives < 1 )
         {
             if ( PlayerPrefs.HasKey( "Time" ) )
             {
                 time = Convert.ToDateTime( PlayerPrefs.GetString( "Time" ) );
                 
                 difference = DateTime.Now - time;

                 if ( difference.Minutes > 14 )
                 {
                     Lives.Lives = Lives.lives + 3;
                     notice.SetActive( false ); if ( PlayerPrefs.HasKey( " Life Counter" ) ) { PlayerPrefs.SETINT( "ContadorVidas", lives.Lives ); }
                 }
             }

             if ( difference.Minutes < 15 && Lives.Lives < 1 )
             {
                 notice.SetActive( true );
                 chrono.SetActive( true );
                 text.text = "You have no lives, expected time" + difference.Minutes.ToString() + "15 Minutes";
             }
         }
     }        

That is what I have done for time management. As you can see, it's quite simple in essence but I do not know how to cut the loop. I have tried adding several conditions with respect to the lives, that is, in the Start for example, add an if with the variable lives as a trigger, but without any type of result.

The problem is located, I'm sure, because that's what the console of unity shows me, but I do not have problems to solve it. As you may have noticed, my programming style is far from being polished, but with time I hope to continue improving it.

I await any response and all help is welcome.

Thank you very much for your time and greetings

SenPerfect