Object reference not set to instance for my timer and my text

I am making a game where the player has to fill up a hunger and thirst percentage level both to 100% before a 30 second timer runs out. The player has to eat either a jaguar or a plant. There are anti-jaguars in the game, which you must avoid otherwise you will fail the game if you touch the anti-jaguar. The regular jaguar gains the hunger by 20% and the plan gains the hunger by 10%. Touching a body of water gains the thirst by 20%. There are texts on the screen showing the thirst and hunger percentage and how many regular jaguars you ate. The latest thing I even added to the game was the timer and its text. Before I added the timer to the game, the game had a problem where it would start paused due to an error about the thirst text not sent to an instance of an object. Then, the game would work if I unpause it. Now the timer is giving me a problem where the game would start paused and when I continuously hit the unpause button, it won't unpause, but the timer text is showing that the time has elapsed (It's basically pausing by frame). NOTE: Jaguars are tagged as "PickUp" in this game. Here are the errors:

1. NullReferenceException: Object reference not set to an instance of an object CompletePlayerController.SetThirstText () (at Assets/_Completed-Assets/Scripts/CompletePlayerController.cs:150) CompletePlayerController.Start () (at Assets/_Completed-Assets/Scripts/CompletePlayerController.cs:43)

2. NullReferenceException: Object reference not set to an instance of an object CompletePlayerController.SetTimerText () (at Assets/_Completed-Assets/Scripts/CompletePlayerController.cs:175) CompletePlayerController.Update () (at Assets/_Completed-Assets/Scripts/CompletePlayerController.cs:56)

Here is my CompletePlayerController code:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine.SceneManagement;
  
 
 //Adding this allows us to access members of the UI namespace including Text.
 using UnityEngine.UI;
 
 public class CompletePlayerController : MonoBehaviour
 {
 
     public float speed;             //Floating point variable to store the player's movement speed.
     public Text winText;            //Store a reference to the UI Text component which will display the 'You win' message.
     public Text thirstText;
     public Text hungerText;
     public Text timerText;
 
     private Rigidbody2D rb2d;       //Store a reference to the Rigidbody2D component required to use 2D Physics.
     
     private int thirstCount;
     private int hungerCount;
     Rigidbody2D bullet;
     float speed2 = 30f;
     float timeLeft;
     
 
 
     // Use this for initialization
     void Start()
     {
         //Get and store a reference to the Rigidbody2D component so that we can access it.
         rb2d = GetComponent<Rigidbody2D> ();
         
         
 
         //Initialize counts to zero and starts timer from 30 seconds.
         
         thirstCount = 0;
         hungerCount = 0;
         timeLeft = 30.0f;
         
         SetThirstText();
         SetHungerText();
         SetTimerText();
         
        
 
 
 
     }
     
     void Update()
     {
         timeLeft -= Time.deltaTime;
         SetTimerText();
          if(timeLeft < 0)
          {
              
              RestartScene();
          }
     }
 
     //FixedUpdate is called at a fixed interval and is independent of frame rate. Put physics code here.
     void FixedUpdate()
     {
         //Store the current horizontal input in the float moveHorizontal.
         float moveHorizontal = Input.GetAxis ("Horizontal");
 
         //Store the current vertical input in the float moveVertical.
         float moveVertical = Input.GetAxis ("Vertical");
 
         
 
         //Use the two store floats to create a new Vector2 variable movement.
         Vector2 movement = new Vector2 (moveHorizontal, moveVertical);
 
         //Call the AddForce function of our Rigidbody2D rb2d supplying movement multiplied by speed to move our player.
          rb2d.AddForce (movement * speed);
 
 
     }
 
 
     void OnTriggerEnter2D(Collider2D other) 
     {
         
         if (other.gameObject.CompareTag ("PickUp")) 
         {               
             
             other.gameObject.SetActive(false);
 
             
            
             hungerCount = hungerCount + 20;
             
             
             SetHungerText();
 
             
 
         }
         
         if (other.gameObject.CompareTag("Anti-jaguar"))
         {
             
             
             RestartScene();
         }
 
 
 
         if (other.gameObject.CompareTag ("Water")) 
         {   
 
             SetThirstText ();
 
             
             other.gameObject.SetActive(true);
 
             
             thirstCount = thirstCount + 20;
 
             
 
         }
 
 
 
 
         if (other.gameObject.CompareTag ("Plant")) 
         {   
           
            
             other.gameObject.SetActive(false);
 
             hungerCount = hungerCount + 10;
             SetHungerText ();
             
 
         }   
     }   
 
 
    
 
     void SetThirstText()
     {
         
         thirstText.text = "Thirst: " + thirstCount.ToString () + "%";
         
         
             if (thirstCount >= 100 && hungerCount >= 100)
         {
             
             winText.text = "You win!";
         }
     }
 
     void SetHungerText()
     {
         
         hungerText.text = "Hunger: " + hungerCount.ToString () + "%";
         if (thirstCount >= 100 && hungerCount >= 100)
         {
             
             winText.text = "You win!";
         }
         
 
     }
 
     void SetTimerText()
     {
         timerText.text = "Time left: " + timeLeft.ToString() + " seconds";
     }
 
 
     void RestartScene()
     {
      SceneManager.LoadScene(SceneManager.GetActiveScene().name);
     }
  
 
 
 }