Optimizing door script

So i'm having problems with this script and performance issues with this script and idk what to do.

using UnityEngine; using System.Collections;

public class DoorScript : MonoBehaviour {

 //Door UI Name
 public string doorInteractable = "Interact With Door";
 public string doorInteractableOpen = "Open Door";
 public string doorInteractableClose= "Close Door";
 public string doorInteractableLocked= "Locked Door";

 //If door is open
 public bool isOpen = false; 
 public bool isLocked = false;

 public bool autoClose = false;
 public float autoCloseDelayTime = 5f;
 private float autoCloseDelay;
 
 //Audio
 public AudioClip[] doorSounds;
 public float audioPitch;
 public float audioVolume;

 
 public float doorOpenAngle = 90f;
 public float doorCloseAngle = 0f;
 public float smoothSpeed = 2f;

 //delay
 public float delayTime;
 private float delay;

 public GameObject door;

 
 void Start () 
 {
     delay = delayTime;
     autoCloseDelay = autoCloseDelayTime;

     //Set Interact UI Open/Close
     if (isOpen == false) {
         doorInteractable = doorInteractableOpen;
         } 

     if (isOpen == true) {
         doorInteractable = doorInteractableClose;
         }

     if (isLocked == true) {
         doorInteractable = doorInteractableLocked;
         }


 }

 public void LockDoor(bool lockDoor) {

     if (lockDoor == true) {
         isLocked = true;
         //door.transform.tag = "LockedDoor";
         doorInteractable = doorInteractableLocked;
     } else {
         isLocked = false;
         //door.transform.tag = "Door";
         doorInteractable = doorInteractableOpen;
     }
 }



 public void ChangeDoorState() {

     if (isLocked == false) {
         isOpen = !isOpen;
     }

     if (isOpen == true && isLocked == false) { //Opening
         GetComponent<AudioSource>().pitch = audioPitch;
         GetComponent<AudioSource>().volume = audioVolume;
         GetComponent<AudioSource>().clip = doorSounds[0];
         GetComponent<AudioSource>().Play();
         delay = delayTime;
         doorInteractable = doorInteractableClose;
     }

     if (isOpen == false && isLocked == false) { //Closing
         GetComponent<AudioSource> ().pitch = audioPitch;
         GetComponent<AudioSource> ().volume = audioVolume;
         GetComponent<AudioSource> ().clip = doorSounds [1];
         GetComponent<AudioSource> ().Play ();
         delay = delayTime;
         doorInteractable = doorInteractableOpen;

     }
         if (isLocked == true) { //Locked
             //GetComponent<AudioSource>().pitch = audioPitch;
             //GetComponent<AudioSource>().volume = audioVolume;
             //GetComponent<AudioSource>().clip = doorSounds[2];
             //GetComponent<AudioSource>().Play();;
     }
 }
 

 void Update () {

     if(isOpen == false) { //Closes Door
             Quaternion targetRotation = Quaternion.Euler(0, doorCloseAngle, 0);
             transform.localRotation = Quaternion.Slerp(transform.localRotation, targetRotation, smoothSpeed * Time.deltaTime);
             } 

     if(isOpen == true) { //Open Door
             Quaternion targetRotation = Quaternion.Euler(0, doorOpenAngle, 0);
             transform.localRotation = Quaternion.Slerp(transform.localRotation, targetRotation, smoothSpeed * Time.deltaTime);
                 if (autoClose == true) {
                     delay = delay - Time.deltaTime;
                     if (autoCloseDelay <= 0) {
                         isOpen = false;
                         autoCloseDelay = autoCloseDelayTime;
                         }
                     }

                 if (isLocked == true) {
                     isOpen = false;
                     doorInteractable = doorInteractableLocked;
                 } else {

                     doorInteractable = doorInteractableOpen;
                         }
             }
         
             

             if (autoClose == true && isOpen == true) {
                 autoCloseDelay = autoCloseDelay - Time.deltaTime;
                 }
 
     }
 

}