How to control missile/knife (Quaternion.Euler)

Hi,

I am making a game where the player is able to throw a knife and then control the knife, from a first person view, by moving the mouse. When the player throws a knife, a new "knife-camera" is instatiated, and I can see that it is looking in the same direction as the player (which is what I want). But as soon as the first update (within the knife script) is called, the view shifts to some default position.

The update function can be seen here:

 void Update()
     {
         if (!hasHit )
         {
             if (isBeingControlled)
             {
 
                 //float mousePosX = Input.GetAxis("Mouse X") + screenCenter.x;
                 //float mousePosY = Input.GetAxis("Mouse Y") + screenCenter.y;
 
                 float mouseX = Input.GetAxis("Mouse X") * mouseSensitivity * Time.deltaTime;
                 float mouseY = Input.GetAxis("Mouse Y") * mouseSensitivity * Time.deltaTime;
 
                 xRotation -= mouseY;
                 xRotation = Mathf.Clamp(xRotation, -90f, 90f);
                 yRotation += mouseX;
 
                 transform.localRotation = Quaternion.Euler(xRotation, yRotation, 0f);
 
                 transform.position += transform.forward * speed * Time.deltaTime;
 
                 if (Input.GetKeyDown(KeyCode.Q))
                 {
                     isBeingControlled = false;
                     speed = 20f;
                     ActivatePlayer();
                 }
             }
 
             else
             {
                 transform.position += transform.forward * speed * Time.deltaTime;
             }
 
         }
 
     }

If I remove, transform.localRotation = Quaternion.Euler(xRotation, yRotation, 0f);, I can see that the knife is flying in the "correct" direction, but then I cannot control the knife.

Am I missing something, or can I do this in an easier way.

Thank you in advance!