Why is my Unity Camera getting messed up whenever I add a lookaround code in c#

Question

My unity camera is parented with the gun so the gun is supposed to be on the side but whenever I add my lookaround script my unity camera goes to the center of the gun not the side.

Lookaround script:

using System.Collections.Generic;
using UnityEngine;

public class MouseLook : MonoBehaviour
{

public float mouseSensitivity = 100f;
public Transform playerBody;
float xRotation = 0f;

    void Start() 
    {
Cursor.lockState = CursorLockMode.Locked;
    }
    
    
    void Update()
    {

       float mouseX = Input.GetAxis ("Mouse X") * mouseSensitivity * Time.deltaTime;
       float mouseY = Input.GetAxis ("Mouse Y") * mouseSensitivity * Time.deltaTime;

       xRotation -= mouseY;
       xRotation = Mathf.Clamp(xRotation, -90f, 90f);

       transform.localRotation = Quaternion.Euler(xRotation, 0f, 0f);
       playerBody.Rotate(Vector3.up * mouseX);
    }
}

For the gun I just parented the camera with it but now whenever I run the game it automatically puts my camera in the middle of the gun. By the way my code language is C#.