Cannons wont move on the vertical axis

My cannon script:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Cannon : MonoBehaviour
 {
     public GameObject barrel;
     private int LookVertical;
     private int LookHorizontal;
     public GameObject cannonBall;
     public Transform spawn;
     public int thrust;
     public float degrees;
     public Rigidbody CannonBallRb;
 
     void Start()
     {
     }
 
     // Update is called once per frame
     void Update()
     {
         degrees = barrel.transform.rotation.x;
         if (CheckingForInteractions.HighlightCannon == true)
         {
             barrel.GetComponent<Renderer>().material.color = Color.red;
         }
         else if (CheckingForInteractions.HighlightCannon == false)
         {
             barrel.GetComponent<Renderer>().material.color = Color.blue;
         }
 
         if (CheckingForInteractions.UsingCannons == true)
         {
             Debug.Log("cannons");
             barrel.transform.Rotate(LookHorizontal, 0, 0);
 
             if (Input.GetKey(KeyCode.UpArrow) && barrel.transform.rotation.x < 0.95)
             {
                 LookHorizontal = 20;
             }
             else if (Input.GetKey(KeyCode.DownArrow) && barrel.transform.rotation.x > 0.75)
             {
                 LookHorizontal = -20;
             }
             else
             {
                 LookHorizontal = 0;
             }
 
             if (Input.GetKeyDown(KeyCode.Space))
             {
                 FireCannon();
             }
         }
         void FireCannon()
         {
             spawn.rotation = barrel.transform.rotation;
             GameObject clone = Instantiate(cannonBall, spawn.position, spawn.rotation) as GameObject;
             CannonBallRb = clone.GetComponent<Rigidbody>();
             CannonBallRb.AddForce(-transform.forward * thrust * 500);
         }

Everything else works except for firing up and down.