Build crashes when I attack enemy

I keep getting a null reference exception whenever an enemy is destroyed. I've done some tinkering but still haven't found the problem. Here's the script.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.SceneManagement;
 
 
 public class PlayerA : MonoBehaviour
 {
     //PlayerMove
     private Transform myTransform;
     private Vector3 destinationPosition;
     private float destinationDistance;
 
     public float moveSpeed;
 
     //PlayerHealth
     public float maxHealth;
     public float health;
 
     //PlayerAttack
     private GameObject attackingenemy;
     public float attackTimer;
     private float currentAttackTimer;
     private bool attacked;
     private float dist;
     public float range;
 
 
     //PlayerAction
     private float damage;
     public float minDamage;
     public float maxDamage;
 
     //NPC Interaction
     private bool triggeringenemy;
    private bool followingenemy;
 
 
     // Start is called before the first frame update
     void Start()
     {
         
         myTransform = transform;
         destinationPosition = myTransform.transform.position;
         currentAttackTimer = attackTimer;
         health = maxHealth;
         attackingenemy = GameObject.FindGameObjectWithTag("Enemy");
 
 
     }
 
     // Update is called once per frame
     void Update()
     {
    
 
         RaycastHit hit;
 
         destinationDistance = Vector3.Distance(destinationPosition, myTransform.position);
 
         if (destinationDistance < 0.5f)
         {
             moveSpeed = 0;
             
         }
         else if (destinationDistance > 0.5f)
         {
             moveSpeed = 10;
         }
 
         
         if (Input.GetMouseButtonDown(0) && GUIUtility.hotControl == 0)
         {
             Plane playerPlane = new Plane(Vector3.up, myTransform.position);
             Ray ray = UnityEngine.Camera.main.ScreenPointToRay(Input.mousePosition);
             float hitdist = 0.0f;
 
 
             if (playerPlane.Raycast(ray, out hitdist))
             {
                 Vector3 targetPoint = ray.GetPoint(hitdist);
                 destinationPosition = ray.GetPoint(hitdist);
                 Quaternion targetRotation = Quaternion.LookRotation(targetPoint - transform.position);
                 myTransform.rotation = targetRotation;
 
                 if (Physics.Raycast(ray, out hit))
                 {
                     if (hit.collider.tag == "Enemy")
                     {
                         attackingenemy = hit.collider.gameObject;
 
                         followingenemy = true;
                     }
                     else
                     {
                         attackingenemy = null;
                         followingenemy = false;
                     }
                 }
 
             }
         }
 
 
        
         if (triggeringenemy)
         {
             Attack();
         }
 
 
 
         if (currentAttackTimer <= 0)
         {
             currentAttackTimer = attackTimer;
             currentAttackTimer -= 1 * Time.deltaTime;
             attacked = false;
         }
 
         if (destinationDistance > 0.5f)
         {
             myTransform.position = Vector3.MoveTowards(myTransform.position, destinationPosition, moveSpeed * Time.deltaTime);
 
 
         }
 
         if (health <= 0)
         {
             Die();
         }
 
         if (health <= 0)
         {
             SceneManager.LoadScene("MM");
         }
 
        
      
     }
 
     public void Move()
     {
         if (followingenemy)
         {
             if (!triggeringenemy)
             {
                 transform.position = Vector3.MoveTowards(transform.position, attackingenemy.transform.position, moveSpeed);
                 this.transform.LookAt(attackingenemy.transform);
             }
             else
             {
                 Attack();
             }
         }
     }
 
 
    public void Attack()
    {
         if (!attacked)
         {
             damage = Random.Range(minDamage, maxDamage);
            
             attacked = true;
             
         }
         if(attackingenemy)
         {
             myTransform.LookAt(attackingenemy.transform);
             attackingenemy.GetComponent<Enemy1>().health -= damage;
             Debug.Log("Enemy is attacked");
         }
      
 
       
 
    }
 
 
 
         
 
 
     void OnTriggerEnter(Collider other)
     {
 
         if (other.tag == "Enemy")
         {
             triggeringenemy = true;
 
         }
 
         if (other.tag == "Enemy")
         {
             attackingenemy = other.gameObject;
         }
 
     }
 
     void OnTriggerExit (Collider other)
     {
         if (other.tag == "Enemy")
         {
             triggeringenemy = false;
 
         }
     }
 
 
     public void Die()
     {
         if (health <= 0)
         {
             Destroy(this.gameObject);
             print("Player has been destroyed");
         }
         
     }
 }