While loop yield lag?

I'm trying to make a script that when I use a melee attack, the player moves towards the enemy unless he is within a specific distance to him, and the enemy is also pushed back, regardless of position.

I got it to work.. the only problem is that it seems that because I have a nested while loop... It seems to have the first frame lag for a noticeable split-second before working as it should.

This lag is a problem, since I can't have the game lag every time the player wants to melee. Is there any reason besides a slow cpu that this would happen, I really doubt my computer wouldn't be able to handle this, and is there any way I can make it more efficient?

 var cooldownTimer: float = 10.0; //This will be changed in inspector
 var countDown : float = 0.0;
 var playerAttackRange : int = 5;
 var particle : GameObject;
 var player : GameObject;
 var particleClone = particle;
 var slashDistance : float = 1.0;
 var moveDirection;
 var shouldMove : boolean = true;
 var controller : CharacterController;
 private var currentPosition : Vector3;
 var swordSlash : AudioClip;
 var hit : RaycastHit;
 var hitLoc;
 var impact;
 var attackBool : boolean = false;
 
 function Start () {
 
 }
 
 function Update () {
     
     currentPosition = transform.position;
     
     moveDirection = player.transform.forward;
     
     if(Input.GetButton("Fire1") &&  Time.time > countDown){
                 
         attack();
         
     }
         
 }
 
 
 function attack(){
   if(AbilitySystem.fireElement.equippedFire == true) {
     audio.PlayOneShot(swordSlash);
     countDown = Time.time + cooldownTimer;
     var fwd = transform.forward; // <- easier way to get the forward direction
     if(Physics.Raycast(transform.position, fwd, hit, playerAttackRange)){
       Debug.Log("Melee has struck " + hit.collider.name + " at a range of " + playerAttackRange +"!!!!!!!!!!!");
       if(hit.collider.tag == "Enemy") {
         hit.collider.GetComponent(EnemyHealth).enemyCurrentHealth -= AbilitySystem.fireElement.swordDamage;
         particleClone = Instantiate(particle, hit.transform.position, hit.transform.rotation);
         Destroy(particleClone, 1);
         hitLoc = hit.point;
         // calculate the direction to push the target:
         impact = -hit.normal;
         impact.y = 0; // keep it horizontal
         impact.z = 0; // keep it 2d
         impact = impact.normalized;
         // apply the movement during duration seconds:
         var duration = 0.25;
         var durationTwo = duration;    
         while (duration > 0){
             Debug.Log("While loop one started");
             while (durationTwo > 0){
                 Debug.Log("While loop two started");
                 if(Vector3.Distance(transform.position, hitLoc) > slashDistance){    
                     player.transform.Translate(impact.x * Time.deltaTime * 4, impact.y, impact.z, Space.World);
                     Debug.Log("Player transformed");
                 }
                 durationTwo -= Time.deltaTime;
                 Debug.Log("DurationTwo = " + durationTwo);
             }     
             hit.transform.Translate(impact * Time.deltaTime * 4, Space.World);  
             Debug.Log("Enemy transformed");         
               duration -= Time.deltaTime; // count time
               Debug.Log("Duration = " + duration);
               Debug.Log("yielding");
               yield; // return to loop next frame
         }
       }
     }
   }
 }