Really need some help with my bullets firing opposite and not following rotation.

Hi, I've posted this before. I have a script that shoots my bullets backwards (please look at attached GIF to see what happens). I think it's because transform.forward is meant to be used in first-person games, not side scrolling shooters. I was thinking of trying the Raycast method to make the bullets follow the Raycast but I was thinking maybe a small change in code might help. The cannon rotates too so I need the bullets to fly straight to the right while following rotation. Thanks so much for your help, this has been killing me for months!!! Here's the Code and GIF.

https://1drv.ms/i/s!AmyWRzQWVcyPg4QBP8AUzSWWS2FHrg

 using UnityEngine;
 using System.Collections;
 
 public class Bullet : MonoBehaviour {
     public float CannonSpeed;
     public GameObject bulletSpawn;
     public GameObject bulletInstance;
     public float Bullet_Forward_Force;
     public float bulletTimer;
     public float minAngle, maxAngle;
 
     // Use this for initialization
     void Start () {
     
     }
 
     Quaternion ClampRotationAroundXAxis(Quaternion q, float min, float max)
 
 {
         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, min, max);
         q.x = Mathf.Tan(0.5f * Mathf.Deg2Rad * angleX);
         return q;
     }
     
     // Update is called once per frame
     void Update () {
 
     transform.rotation = ClampRotationAroundXAxis(transform.rotation, minAngle, maxAngle);
 
         if (Input.GetKey (KeyCode.Q)) 
 
         {
             transform.Rotate(Vector3.left * Time.deltaTime * CannonSpeed);
         }
 
 
 
 
 
 
         if (Input.GetKey (KeyCode.A))
 
         {
             transform.Rotate(Vector3.right * Time.deltaTime * CannonSpeed);
         }
 
 
 
         bulletTimer -= Time.deltaTime;
         if (bulletTimer <=0){
 
             bulletTimer = 0;
         }
     
         if (Input.GetKey(KeyCode.Tab) && bulletTimer == 0)
             
         {
             GameObject Temporary_Bullet_Handler;
             Temporary_Bullet_Handler = Instantiate(bulletInstance,bulletSpawn.transform.position,bulletSpawn.transform.rotation) as GameObject;
             bulletTimer = 0.2f;
             //Sometimes bullets may appear rotated incorrectly due to the way its pivot was set from the original modeling package.
             //This is EASILY corrected here, you might have to rotate it from a different axis and or angle based on your particular mesh.
             Temporary_Bullet_Handler.transform.Rotate(Vector3.left * 90);
 
             //Retrieve the Rigidbody component from the instantiated Bullet and control it.
             Rigidbody Temporary_RigidBody;
             Temporary_RigidBody = Temporary_Bullet_Handler.GetComponent<Rigidbody>();
 
             //Tell the bullet to be "pushed" forward by an amount set by Bullet_Forward_Force.
             Temporary_RigidBody.AddForce(transform.forward * Bullet_Forward_Force);
 
             //Basic Clean Up, set the Bullets to self destruct after 10 Seconds, I am being VERY generous here, normally 3 seconds is plenty.
             Destroy(Temporary_Bullet_Handler, 4.0f);
 
         }
     
     }
 }