Damager Powerup issue - NullReferenceException: Object reference not set to an instance of an object

Hi all, I am currently creating a damage powerup, so when my player collides with an object it will increase the damage essentially. I have used this method for other powerups but for some reason it is not linking this one.

My powerup code is

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class damagePowerup : MonoBehaviour {
 
     public int damageIncrease = 10;
 
     void Update () {
         gameObject.transform.Rotate (new Vector3(0, 30, 0) * Time.deltaTime);
     }
 
     public void OnTriggerEnter(Collider other) {
 
         if (other.tag == "Player") {
             Debug.Log("Damage Powerup");
             PlayerShooting NewDamage = other.gameObject.GetComponent<PlayerShooting> ();
             NewDamage.damagePerShot = damageIncrease;
             transform.position = new Vector3(10000, 10000, 100000);
             StartCoroutine ("WaitTime", NewDamage);
         }
     }
 
     public IEnumerator WaitTime(PlayerShooting playerDamage) {
         yield return new WaitForSeconds (5);
         playerDamage.damagePerShot = 100;
         Destroy (gameObject);
     }
 }
 

and my PlayerShooting script that I am accessing is

 using UnityEngine;
 
 public class PlayerShooting : MonoBehaviour
 {
     public int damagePerShot = 20;
     public float timeBetweenBullets = 0.15f;
     public float range = 100f;
 
 
     float timer;
     Ray shootRay;
     RaycastHit shootHit;
     int shootableMask;
     ParticleSystem gunParticles;
     LineRenderer gunLine;
     AudioSource gunAudio;
     Light gunLight;
     float effectsDisplayTime = 0.2f;
 
 
     void Awake ()
     {
         shootableMask = LayerMask.GetMask ("Shootable");
         gunParticles = GetComponent<ParticleSystem> ();
         gunLine = GetComponent <LineRenderer> ();
 //        gunAudio = GetComponent<AudioSource> ();
     }
 
 
     void Update ()
     {
         timer += Time.deltaTime;
 
         if(Input.GetButton ("Fire1") && timer >= timeBetweenBullets && Time.timeScale != 0)
         {
             Shoot ();
         }
 
         if(timer >= timeBetweenBullets * effectsDisplayTime)
         {
             DisableEffects ();
         }
     }
 
 
     public void DisableEffects ()
     {
         gunLine.enabled = false;
     }
 
 
     public void Shoot ()
     {
         timer = 0f;
 
 //        gunAudio.Play ();
         gunParticles.Play ();
 
 
         gunLine.enabled = true;
         gunLine.SetPosition (0, transform.position);
 
         shootRay.origin = transform.position;
         shootRay.direction = transform.forward;
 
         if(Physics.Raycast (shootRay, out shootHit, range, shootableMask))
         {
             EnemyHealth enemyHealth = shootHit.collider.GetComponent <EnemyHealth> ();
             if(enemyHealth != null)
             {
                 enemyHealth.TakeDamage (damagePerShot, shootHit.point);
             }
             gunLine.SetPosition (1, shootHit.point);
         }
         else
         {
             gunLine.SetPosition (1, shootRay.origin + shootRay.direction * range);
         }
     }
 
 }
 

The error I am getting when playing the game is NullReferenceException: Object reference not set to an instance of an object damagePowerup.OnTriggerEnter (UnityEngine.Collider other) (at Assets/Scripts/damagePowerup.cs:18)

I do not understand why it doesn't like this line of code as I am accessing the script, getting the variable I want and added a new value?

If someone could help me out that would be great!