arrow shooting

Hi. I've got some problems on managing arrow shooting, meaning i'm executing a draw animation ending in aiming position. staying there as long as i keep R-Key pressed. Releasing "R" the arrow is instantiate and shooted. So far so good, but I want to prevent the arrow to be shooted since the draw animation is finished, i don't want to use my bow as a 30 arrow per second machine gun...

public bool IsNocked { get; set; }

Start{ IsNocked = false; }

Update{ ShootArrow(); }

 private void ShootArrow()
 {
     if (AmmoText.ammoAmount > 0)
     {   //if have arrows left  
                   
         if (Input.GetKeyDown(KeyCode.R))
         {
             StartCoroutine(LoadArrow());
         }
         
         if (IsNocked && Input.GetKeyUp(KeyCode.R))
         {
             nockArrowPrefab.gameObject.SetActive(false);
             playerAnimations.Release_Range();
             //Istanzio una nuova freccia nella posizione dell'arrowspawnpoint e la chiamo go
             GameObject go = Instantiate(arrowPrefab, spellSpawn.position, Quaternion.identity);
             Rigidbody rb = go.GetComponent<Rigidbody>();
             rb.velocity = cam.transform.forward * shootForce;
             AmmoText.ammoAmount -= 1;
             crossair.SetActive(false);
             IsAttacking = false;
             IsNocked = false;
         }
         if (!IsNocked && Input.GetKeyUp(KeyCode.R))
         {
             
             nockArrowPrefab.gameObject.SetActive(false);
             playerAnimations.Release_Range();//anim release
             crossair.SetActive(false);
             IsAttacking = false;
             IsNocked = false;
             return;
         }

     }
     else
         return;
 }
 public IEnumerator LoadArrow()
 {
     crossair.SetActive(true);
     //showing fake arrow for the animation
     nockArrowPrefab.gameObject.SetActive(true);
     playerAnimations.Attack_Range(); //animation draw
     IsNocked = true;
     yield return new WaitForSeconds(0.5f);
 }