Uncommon Text behaviour

Hello, I have a little problem with my Text component. In my game i have a int that is number of killed enemies from start game. I had to use [System.NonSerialized] because it was acting like static (it wasnt..), but point is that variable killedEnemies is increasing, while Text component is still at start value, until i stop the game - then its updating to last score. I was trying almost every solution i found and its still not working. Please, help me, because it doesnt look hard but i spend last days fighting with that.

For addition i have to mention that Health variable is working fine, for both float and text variable.

 using UnityEngine;
 using UnityEngine.UI;
 using System.Collections;
 
 public class PlayerController : MonoBehaviour 
 {
     public GameObject bullet;
 
     private float health;
     public float damage;
     private int score;
 
     [System.NonSerialized]
     private int killedEnemies;
 
     private float speedHorizontal = 0.035f;
     private float speedVertical = 0.03f;
     private Vector2 size;
 
     //CAMERA//
     private Vector3 bottomLeft;
     private Vector3 topRight;
     private Rect cameraRect;
     //CAMERA//
 
     private Text healthText;
     private Text enemiesText;
     private Text scoreText;
 
     void Awake()
     {
         score = 0;
         killedEnemies = 0;
     }
     void Start () 
     {
         damage = 20.0f;
         health = 100.0f;
 
         size = GetComponent<BoxCollider2D> ().size;
 
         bottomLeft = Camera.main.ScreenToWorldPoint(Vector3.zero);
         topRight = Camera.main.ScreenToWorldPoint(new Vector3(Camera.main.pixelWidth, Camera.main.pixelHeight));
         cameraRect = new Rect(bottomLeft.x, bottomLeft.y, topRight.x - bottomLeft.x, topRight.y - bottomLeft.y);
 
         healthText = GameObject.Find ("HealthText").GetComponent<Text> ();
         enemiesText = GameObject.Find ("EnemiesText").GetComponent<Text> ();
         scoreText = GameObject.Find ("ScoreText").GetComponent<Text> ();
     }
 
     void Update()
     {
         updateTexts ();
     }
 
     void FixedUpdate () 
     {
         controlBorders ();
         checkIfDie ();
 
         if (Input.GetKey (KeyCode.W)) 
         {
             transform.Translate(new Vector3(0.0f, speedVertical, 0.0f));
         }
         if (Input.GetKey (KeyCode.S)) 
         {
             transform.Translate(new Vector3(0.0f, -speedVertical, 0.0f));
         }
         if (Input.GetKey (KeyCode.A)) 
         {
             transform.Translate(new Vector3(-speedHorizontal, 0.0f, 0.0f));
         }
         if (Input.GetKey (KeyCode.D)) 
         {
             transform.Translate(new Vector3(speedHorizontal, 0.0f, 0.0f));
         }
         if (Input.GetKeyDown (KeyCode.Space)) 
         {
             shoot ();
         }
         if (Input.GetKeyDown (KeyCode.K)) 
         {
             //enemyKilled ();
         }
     }
 
     void controlBorders()
     {
         transform.position = new Vector3(
             Mathf.Clamp(transform.position.x, cameraRect.xMin + size.x/4, cameraRect.xMax - size.x/4),
             Mathf.Clamp(transform.position.y, cameraRect.yMin + size.y/4, cameraRect.yMax - size.y/4),
             transform.position.z);
     }
 
     public void takeHealth(float hea)
     {
         if ((health + hea) > 100) 
         {
             health = 100;
         } 
         else 
         {
             health += hea;
         }
     }
 
     void shoot()
     {
         Vector3 tempPos = transform.position;
         tempPos.x += 1.0f;
         Instantiate (bullet, tempPos, Quaternion.identity);
     }
 
     public void takeHit(float dam)
     {
         health -= dam;
         Debug.Log ("Took hit " + dam);
     }
 
     public void enemyKilled()
     {
         score += 1;
         killedEnemies += 1;
         Debug.Log (killedEnemies);
     }
 
     void checkIfDie()
     {
         if (health <= 0) 
         {
             Destroy (this.gameObject);
         }
     }
     void updateTexts()
     {
         healthText.text = "Health: " + health;
         enemiesText.text = "Killed: " + killedEnemies;
         scoreText.text = "Score: " + score;
     }
 }