I'm having trouble clamping the rotation of the camera?

Hello, I seem to be having some trouble integrating a function that I took from the MouseLook script that comes with importing the Characters package. Currently, it does not seem to be doing anything, but I would like it to limit the x of the camera rotation to only be -90 to 90. I'll put slashes after the important lines, the rest is working fine.

 using UnityEngine;
 using System;
 using System.Collections;
 
 public class CameraMouseLook : DavidBehaviour{
 
     Vector2 MouseLook;
     Vector2 SmoothV;
     public float Sensitivity = 5;
     public float Smoothing = 2;
 
     public bool CanMove;
 
     void Update(){
         Camera.main.transform.localRotation = ClampRotationAroundXAxis (Camera.main.transform.localRotation);//
 
         if (CanMove) {
             var MD = new Vector2 (Input.GetAxisRaw ("Mouse X"), Input.GetAxisRaw ("Mouse Y"));
 
             MD = Vector2.Scale (MD, new Vector2 (Sensitivity * Smoothing, Sensitivity * Smoothing));
             SmoothV.x = Mathf.Lerp (SmoothV.x, MD.x, Smoothing);
             SmoothV.y = Mathf.Lerp (SmoothV.y, MD.y, Smoothing);
             MouseLook += SmoothV;
 
             Camera.main.transform.localRotation = Quaternion.AngleAxis (-MouseLook.y, Vector3.right);
             transform.localRotation = Quaternion.AngleAxis (MouseLook.x, transform.up);
         }
     }
     Quaternion ClampRotationAroundXAxis(Quaternion q)//
     {//
         q.x /= q.w;//
         q.y /= q.w;//
         q.z /= q.w;//
         q.w = 1.0f;//
 
         float angleX = 2.0f * Mathf.Rad2Deg * Mathf.Atan (q.x);//
 
         angleX = Mathf.Clamp (angleX, -90, 90);//
 
         q.x = Mathf.Tan (0.5f * Mathf.Deg2Rad * angleX);//
 
         return q;//
     }//
 }