On collision with enemy slow player down while inside the collision box, else normal speed.

Hiya guys this is the code for movement for my Main Player.

 using UnityEngine;
 using System.Collections;
 
 
 public class NewBehaviourScript : MonoBehaviour
 {
 
     public float moveSpeed = 1f;
 
     void Update()
     {
         Vector3 moveInput = new Vector3(Input.GetAxis("Horizontal"), 0f, -Input.GetAxis("Vertical"));
         Vector3 moveVelocity = moveInput * moveSpeed;
         gameObject.transform.position += moveVelocity;
 
         float angle = Mathf.Atan2(Input.GetAxisRaw("Horizontal2"), -Input.GetAxisRaw("Vertical2")) * Mathf.Rad2Deg;
         if (Input.GetAxis("Horizontal2")!= 0||-Input.GetAxis("Vertical2")!=0);
         {
             gameObject.transform.rotation = Quaternion.AngleAxis(angle, gameObject.transform.up);
 
         }
     }
 }

What I am trying to do is, when the Main character collides with my an Enemy, while in its collision boss I want the moveSpeed to be halved until its out of the collision box where normal movespeed will be returned. I have tried this

 using UnityEngine;
 using System.Collections;
 
 
 public class NewBehaviourScript : MonoBehaviour
 {
 
     public float moveSpeed = 1f;
    // public GameObject Bullet_Emitter;
    // public GameObject Projectile;
    // public float Bullet_Forward_Force;
 
     void Update()
     {
         Vector3 moveInput = new Vector3(Input.GetAxis("Horizontal"), 0f, -Input.GetAxis("Vertical"));
         Vector3 moveVelocity = moveInput * moveSpeed;
         gameObject.transform.position += moveVelocity;
 
         float angle = Mathf.Atan2(Input.GetAxisRaw("Horizontal2"), -Input.GetAxisRaw("Vertical2")) * Mathf.Rad2Deg;
         if (Input.GetAxis("Horizontal2")!= 0||-Input.GetAxis("Vertical2")!=0);
         {
             gameObject.transform.rotation = Quaternion.AngleAxis(angle, gameObject.transform.up);
 
         }
 
  
     }
 
     void OnCollisionEnter(Collision collision)
     {
         if (gameObject.tag == "Fungus")
         {
             Debug.Log("HIT");
             moveSpeed /= 2f;
         }
     }
 }

Any help would be appreciated! Thank you!