plz help

failRotate.cs

            Vector3 startingPosWorld = this.hookParent.position;
            Vector3 mouse = Input.mousePosition;
            Vector3 startingPos = Camera.main.WorldToScreenPoint(startingPosWorld);

            Vector3 vectorToTarget = mouse - startingPos;
            float angle = Mathf.Atan2(vectorToTarget.y, vectorToTarget.x) * Mathf.Rad2Deg;
            Quaternion q = Quaternion.AngleAxis(angle, Vector3.forward);
            this.hookParent.transform.rotation = q;