Implementing a "Fire Mode" in 2D

Making an artillery game and I want there to be a shot mode on keypress.

Have had a working projectile fire but I am having trouble getting it to work with update, I'm not sure where exactly I'm going wrong... can anyone help with this? {

 public Transform firepoint;
 public GameObject shell;
 public GameObject clone;
 public Camera playcam;
 private float vforce;
 private float hforce;
 bool h;
 void Start()
 {
 }

 // Update is called once per frame
 void Update()
 {
     if (Input.GetButtonDown("Fire1"))
     {
         ShootMode();
     }

     if (Input.GetButtonDown("CamChange"))
     {
         CamChange();
     }
 }

 private void CamChange()
 {
     if (GameObject.Find("MainCam").GetComponent<Camera>().enabled == true)
     {
         GameObject.Find("MainCam").GetComponent<Camera>().enabled = false;
         playcam.enabled = true;
         return;
     }
     if (playcam.isActiveAndEnabled == true)
     {
         GameObject.Find("MainCam").GetComponent<Camera>().enabled = true;
         playcam.enabled = false;
         return;
     }
 }

 void ShootMode()
 {
     GetComponent<playermovement>().enabled = false;
     bool h = GetComponent<playermovement>().facingRight;
     hforce = 0;

     bool exitSM = false;

     while (!exitSM)
     {
         if (Input.GetButtonDown("Fire1"))
         {
             GetComponent<playermovement>().enabled = true;
             exitSM = true;
         }

         if (Input.GetButtonDown("Jump"))
         {
             if (hforce > 5)
             {
                 hforce = 5;
             }
             if (hforce < 0)
             {
                 hforce = 0;
             }
             fire();
             exitSM = true;
         }
         if (Input.GetButtonDown("Horizontal"))
         {
                 hforce = hforce + Input.GetAxis("Horizontal");   
         }
      
     }
 }

 void fire()
 {
     clone = Instantiate(shell, firepoint.position, firepoint.rotation) as GameObject;
     clone.AddComponent<Destructible2D.OnCollision>();
     clone.SetActive(true);
     if (h == false)
     {

         clone.GetComponent<Rigidbody2D>().AddForce(new Vector2(hforce * -100, vforce*10));

     }

     if (h == true)
     {
         clone.GetComponent<SpriteRenderer>().flipX = true;
         clone.GetComponent<Rigidbody2D>().AddForce(new Vector2(hforce *100, vforce*10));

     }
     GetComponent<playermovement>().enabled = true;

 }
 }