Cannot instantiate rotation on Prefab

Evening, all.

I am creating a 2D platformer game in which the player shoots in the direction of where the mouse is pointing at. I am trying to set the rotation of an instantiated bullet prefab in the direction of where the mouse is pointing. The bullet will correctly travel at _deltaX in the X direction, and _deltaY in the Y direction, but will NOT be instantiated in the direction that I specify.

This ShootController.cs class is attached to the Player. The Player does have their RigidBody rotations frozen though.

Any advice would be greatly appreciated!

    public class ShootController : MonoBehaviour { 
    
        public GameObject bullet;
     GameObject playerObject;
    
     //Attributes for finding the Angle of Attack
     private float _deltaX;
     private float _deltaY;
     private float _radians;
     private float _degrees;

 
 void Start ()
 {
 // Assigns the player position values
 playerPosX = Screen.width  * 0.5f;
 playerPosY = Screen.height * 0.5f - 50.0f;  // This is to properly align the origin
 }
 void Update ()
 {
 // When the PLAYER clicks and Shoots
 if (Input.GetMouseButtonDown(0))
 {
 _deltaX = Input.mousePosition.x - playerPosX;
 _deltaY = Input.mousePosition.y - playerPosY;
 ShootNormalShot();
 }
 }
 void ShootNormalShot(){ 
 _radians = Mathf.Atan(_deltaY/_deltaX);
 _degrees = _radians * Mathf.Rad2Deg;
 
 Vector3 angle = new Vector3(0f,0f, _degrees);
 GameObject projectile = (GameObject)GameObject.Instantiate(bullet, playerObject.transform.position, Quaternion.Euler(angle));
 projectile.GetComponent().Initialize(_deltaX, _deltaY, _normalDamage, _MaxSpeed); 
 }
}

Why not something like:

GameObject projectile = (GameObject)GameObject.Instantiate(bullet, playerObject.transform.position, Quaternion.Euler(_deltaX,_deltaY,degrees));