Character wont turn on keypress

'm making this 3D top-down project, and I need the character to turn with the WASD keys (turn only in those directions, no diagonals), at the moment, the vertical part seems to be turning smoothly, but once I press 'A' or 'D' the player stops turning correctly(even with the 'W' or 'S' keys).

Here's my code so far

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class PlayerMovement : MonoBehaviour
 {
     public CharacterController controller; 
     public float speed = 5f;
     public float gravity = -19f;
     public Transform groundCheck;
     public float groundDistance = 0.4f;
     public LayerMask groundMask;
     public Inventory inventory;
     public int _rotationSpeed = 180;
 
     public GameObject Hand; // to put objects directly on the hand of the player
      
     Vector3 velocity;
     bool isGrounded;
 
     // Update is called once per frame
     void Update()
     {
      HandleShootInput();
         GetKeyPressed();
                  
     }
 
 
     
 
     private void GetKeyPressed()
     {
 
         isGrounded = Physics.CheckSphere(groundCheck.position, groundDistance, groundMask);
 
         
         if (isGrounded && velocity.y < 0)
         {
             velocity.y = -2f;
         }
         float x = Input.GetAxis("Horizontal");
         float z = Input.GetAxis("Vertical");
         if (this.transform.rotation.eulerAngles.y == 0 || this.transform.rotation.eulerAngles.y == 90 || this.transform.rotation.eulerAngles.y == 180 || this.transform.rotation.eulerAngles.y == 270)
         {
             if (Input.GetKey(KeyCode.W))
             {
                 if (this.transform.rotation.eulerAngles.y == 90)
                 {
                     //if in 90º dont rotate
                 }
                 else //else rotate to desired rotation
                 {
 
                     Vector3 rotation = new Vector3(0, 90, 0);
                     this.transform.Rotate(rotation);
 
                 }
                 Vector3 move = transform.forward * z;  // the direction we want to move to
                 controller.Move(move * speed * Time.deltaTime);
 
             }
            
              if (Input.GetKey(KeyCode.S))
             {
                 if (this.transform.rotation.eulerAngles.y == 270)
                 {
                     //if in 90º dont rotate
                 }
                 else //else rotate to desired rotation
                 {
                     Vector3 rotation = new Vector3(0, 270, 0);
                     this.transform.Rotate(rotation);
                 }
                 Vector3 move = transform.forward * (-z);  // the direction we want to move to
                 controller.Move(move * speed * Time.deltaTime);
 
             }
             if (Input.GetKey(KeyCode.D))
             {
                 if (this.transform.rotation.eulerAngles.x == 180)
                 {
                     //if in 90º dont rotate
                 }
                 else //else rotate to desired rotation
                 {
                     Vector3 rotation = new Vector3(0, 180, 0);
                     this.transform.Rotate(rotation);
                 }
                 Vector3 move = transform.forward * z; // the direction we want to move to
                 controller.Move(move * speed * Time.deltaTime);
 
             }
             if (Input.GetKey(KeyCode.A))
             {
                 if (this.transform.rotation.eulerAngles.y == 0)
                 {
                     //if in 90º dont rotate
                 }
                 else //else rotate to desired rotation
                 {
                     Vector3 rotation = new Vector3(0, 0, 0);
                     this.transform.Rotate(rotation);
                 }
 
                 Vector3 move = transform.forward * -z;  // the direction we want to move to
                 controller.Move(move * speed * Time.deltaTime);
 
 
             }
         }
         else
         { 
             
         }
 
     }
 
 
 }