GetKeyDown works only once

Hi, I want to make my character rotate in the direction which he is facing(the game is top view), and I encountered this problem:

Whenever I start the game, I start facing up, and I can press the arrow keys once. When I try to click again, my character moves, but does not rotate.

Right now I just care about rotating character in horizontal axis.

 void Start () {
     rb2d = gameObject.GetComponent<Rigidbody2D> ();
     facingUp = true;
     facingRight = true;
     facingLeft = true;
     facingDown = true;
 }
 
 // Update is called once per frame
 void Update () {
     float horizontal = Input.GetAxis ("Horizontal");
     float vertical = Input.GetAxis ("Vertical");
     HandleMovement (horizontal, vertical);

     Flip (horizontal, vertical);
 }

 private void HandleMovement(float horizontal, float vertical) {
     rb2d.velocity = new Vector2 (horizontal * speed, vertical * speed);
 }
    // this method resets the coordinates of the player
       void Reset() {
     if (!target)
         target = GameObject.FindWithTag("Player");

 }

 if (horizontal < 0 && facingRight || horizontal > 0 && !facingRight && Input.GetKeyDown("right")) {
         Reset ();
         facingRight = !facingRight;
         Vector3 rotationRight = transform.localEulerAngles;
         rotationRight.z = 90;
         transform.localRotation = Quaternion.Euler (0, 0, rotationRight.z);
         Debug.Log (Input.anyKeyDown);
     }

     // left button

     else if (horizontal < 0 && facingLeft || horizontal > 0 && !facingLeft && Input.GetKeyDown("left")) {
         Reset ();
         facingLeft = !facingLeft;
         Vector3 rotationLeft = transform.localEulerAngles;
         rotationLeft.z = -90;
         transform.localRotation = Quaternion.Euler (0, 0, rotationLeft.z);
         Debug.Log ("you pressed left");
     }