A small problem with rotating object at mouse position

Hello. I want to rotate and schoot a bullet on mouse position. Thats my script so far:

  if (Input.GetButtonDown("Fire1"))
         {
                 clickPos = -Vector3.one;
                 Vector3 punktA = new Vector3(1, 2, 0);
                 Vector3 punktB = new Vector3(2, 1, 0);
                 Vector3 punktC = new Vector3(3, 3, 0);
                 Plane plane = new Plane(punktA, punktB, punktC);
                 Ray ray = cam.ScreenPointToRay(Input.mousePosition);
                 float DistanceToPlane;
                 if (plane.Raycast(ray, out DistanceToPlane))
                 {
                     clickPos = ray.GetPoint(DistanceToPlane);
                 }
                 Vector3 finalClickPos = new Vector3(clickPos.x, clickPos.y, 1);
                 Instantiate(bullet, transform.position, Quaternion.LookRotation (finalClickPos));
 
         }

The problem is that this script rotates bullet on opposite direction (when i click upper left it rotates towards upper right). How can i fix it? thanks