Top down rotation using mouse (Two Options 1. Fix my code 2. find a way to have 3D walls

okay so ive recreated my code however there is still one problem [Header("Gun Settings")] public Transform Gun; public Transform RougeLikeParentPlayer; public PlayerMovement RougeLikeParentPlayer_Movement; public float FireRate = 0.1f; public int clipSize = 30; public int ReservedAmmoCapacity = 270;

 [Header("Gun Variables")]
 public bool _Equipeded = false;
 public bool _AutoAim;
 public bool _FullAuto;
 public bool _canShoot;
 public int _Damage;
 public int _CurrentAmmoInClip;
 public int _AmmoInReserve;
 public float _Knockback;
 public LayerMask EnemyMask;

 [Header("Shoot")]
 public KeyCode ShootKey = KeyCode.Mouse1;
 public GameObject Bullet;
 public Bullet BulletScript;
 public GameObject BulletPrefab;
 public GameObject ShootPoint;
 public float BulletSpeed = 1.5f;

 [Header("Aim")]
 public Rigidbody2D Rb;
 public Transform Enemy;
 public bool FacingRight = true;
 public float RotationZ;
 public bool DoNotCallUntilFinished = false;
 public Camera OthoCam;

 // Start is called before the first frame update
 void Start()
 {
     Rb = this.GetComponent<Rigidbody2D>();
     RougeLikeParentPlayer_Movement = RougeLikeParentPlayer.GetComponent<PlayerMovement>();
 }


 // Update is called once per frame
 void FixedUpdate()
 {
     if (_Equipeded == true)
     {
         if (_AutoAim == true)
         {

         }
         else if (_AutoAim == false)
         {
             Vector3 MousePos = new Vector3(Input.mousePosition.x, Input.mousePosition.y, Camera.main.nearClipPlane);

             MousePos = Camera.main.ScreenToWorldPoint(MousePos);

             Debug.Log(MousePos);

             Ray CamRay = Camera.main.ScreenPointToRay(MousePos);
             Plane GroundPlane = new Plane(Vector3.forward, Vector3.zero);
             float RayLength;

             if (GroundPlane.Raycast(CamRay, out RayLength))
             {
                 Vector3 PointToLook = CamRay.GetPoint(RayLength);
                 Debug.DrawLine(CamRay.origin, PointToLook, Color.blue);

                 RotationZ = (Mathf.Atan2(PointToLook.x, PointToLook.y) * Mathf.Rad2Deg) + 90;

                 Debug.Log(RotationZ);

                 if (FacingRight)
                 {
                     transform.localRotation = Quaternion.Euler(0, 0, RotationZ);
                 }
                 else if (!FacingRight)
                 {
                     transform.localRotation = Quaternion.Euler(0, 0, -RotationZ - 180);
                 }
             }

             if (MousePos.x < RougeLikeParentPlayer.position.x && !FacingRight)
             {
                 Flip();
             }
             else if (MousePos.x > RougeLikeParentPlayer.position.x && FacingRight)
             {
                 Flip();
             }
         }

         if (_canShoot == true)
         {
             if (_FullAuto == false && Input.GetKeyDown(ShootKey))
             {
                 Bullet = Instantiate(BulletPrefab, ShootPoint.transform.position, transform.rotation);
                 BulletScript = Bullet.GetComponent<Bullet>();
                 BulletScript.Shooter = Rb;
                 BulletScript.BulletSpeed = BulletSpeed;
             }
             if (_FullAuto == true && Input.GetKey(ShootKey))
             {
                 StartCoroutine(Shoot());
             }
         }
     }
 }

 IEnumerator Shoot()
 {
     _canShoot = false;
     yield return new WaitForSeconds(FireRate);
     Bullet = Instantiate(BulletPrefab, ShootPoint.transform.position, transform.rotation);
     BulletScript = Bullet.GetComponent<Bullet>();
     BulletScript.Shooter = Rb;
     BulletScript.BulletSpeed = BulletSpeed;
     _canShoot = true;
 }

 int i;

 void Flip()
 {
     i++;

     Debug.Log("Flip " + i);

     FacingRight = !FacingRight;
     DoNotCallUntilFinished = false;

     RougeLikeParentPlayer_Movement.CalledFromObject = this.gameObject;
     RougeLikeParentPlayer_Movement.PlayerDirection();
 }

 IEnumerator Delay(float Delay, bool DelayBool)
 {
     yield return new WaitForSeconds(Delay);
     DelayBool = false;
 }

}

the only problem is that if i leave my mouse idle and then move the mouse position does not up date and stays as the old mouse position until i move my mouse but then its still moving from the old position for example i stop moving my mouse at (5,18,8) so i move my character down by five so now the mouse pos should be (5,13,8) but it stays as (5,18,8) then say i move my mouse right by five instead of being (10,13,8) its (10,18,8). i believe this is because it is not to world point? even thought i do use screen to world point as well as the fact that it does not constantly update? only when the mouse is moved by the user?