hello i get an error when i'm trying to acces another variable in a srcipt that is attached to another game object and the error says "NullReferenceException:Object reference not set to an instance of an object" (thankyou in advance :)

 using UnityEngine;
 using System.Collections;
 
 public class celleat : MonoBehaviour {
 
         public GameObject targetObject;
         public  CameraFollow  scriptWantToAcces;
 
 
     private  float Mass = 1f;
 
 
     // Use this for initialization
     void Start () {
          
         scriptWantToAcces =  GameObject.FindGameObjectWithTag("MainCamera").GetComponent< CameraFollow > ();
 
         transform.localScale = new Vector3 (Mass,1,Mass);
         if (scriptWantToAcces = null) {
         
             Debug.Log ("No Script");
         } else {
         
             Debug.Log ("found Script"); //it says this in the debug
         
         }
     }
 
     void Update (){
 
 
 
     }
     
 
 
         void OnTriggerEnter(Collider other) {
 
         if (other.tag == "eatebal") {
             Destroy (other.gameObject);
             Mass += 0.1f;
             transform.localScale = new Vector3 (Mass,1,Mass);
             scriptWantToAcces.offset += 0.1f; // here i get the NullReferenceException:Object reference not set to an instance of an object
 
 
         }
 
 }
 }

heres the script im trying to acces : public class CameraFollow : MonoBehaviour {

      public float offset;
     public GameObject target;
     
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
         Vector3 camTrans = new Vector3 (target.transform.position.x, transform.position.y + offset, target.transform.position.z);
         transform.position = camTrans;
         
         
     }
 
 }