Open Door Animation Problem

I've created a rotating door with these properties:

When I approach the door, I can press "E" to open the door: after that i pressed "E", the animation of opening of the door starts, so the door will be open. Now, if i want close the door i have to re-press "E" on the door, indeed after that i pressed "E", the animation of closing of the door starts, but this animation starts with some seconds of delay. This is a problem because i want that animation starts right after that i pressed "E", without delay.

The script is this:

 using UnityEngine;
 using System.Collections;
 
 public class Rotating_Normal_Door : MonoBehaviour {
     
     public bool open = false;
     public bool interaction = false;
     public bool locked = false;
     
     private Ray ray;
     private Animator anim;
     private int openDoor = Animator.StringToHash("Open");
     
     void Start () 
     {
         anim = GetComponent<Animator> ();
     }
 
     void Update () 
     {
         RaycastHit hit;
         ray = Camera.main.ViewportPointToRay(new Vector3(0.5f, 0.5f, 0));
         if (Input.GetKeyDown ("e") && interaction == true && locked == false && Physics.Raycast (ray, out hit))
             {
                 if(hit.transform.name == name)
                 {
                     changeDoorState ();
                 }
             }
     }
 
     void OnTriggerEnter (Collider col) 
     {
         if (col.gameObject.tag == "Player")
         {
             interaction = !interaction;
         }
     }
 
     void OnTriggerExit (Collider col) 
     {
         if (col.gameObject.tag == "Player")
         {
             interaction = !interaction;    
         }
     }
 
     void changeDoorState ()  
     {
         if (open == false) 
         {
             anim.SetBool (openDoor, true);
             open = true;
         }
         else 
         {
             anim.SetBool (openDoor, false);
             open = false;
         }
     }    
 }
 

Somebody can explain me where am i wrong?