How do i make that the character head to rotate to where the mouse cursor is ?

What i want to do is to rotate the character head only according to where the mouse cursor is at now. So if when the game is running i move the mouse around the game window it will rotate the player head so it will looks like he looking to where i point him to look with the mouse.

And only when moving the mouse cursor around if i don't move the mouse don't rotate the head around.

And i would like first making it for the head only and then also for the whole body to turn to where the mouse cursor is positioning/pointing. But first only for the head part.

I have a ThirdPersonController with MainCamera under it in the Hierarchy. And also attached this script to the ThirdPersonControlle:

 using UnityEngine;
 using System.Collections;
 
 public class CharacterMoveMouse : MonoBehaviour {
 
 
     // Use this for initialization
     void Start () {
     
 
     }
     
     // Update is called once per frame
     void Update () {
     
         Vector3 mousePos = new Vector3(Input.mousePosition.x, Input.mousePosition.z, 10);
         Vector3 lookPos = Camera.main.ScreenToWorldPoint(mousePos);
         lookPos = lookPos - transform.position;
         float angle = Mathf.Atan2(lookPos.z, lookPos.x) * Mathf.Rad2Deg;
         transform.rotation = Quaternion.AngleAxis(angle, Vector3.forward);
 
     }
 }

But this script is not moving the head and when running the game the i see sharp moves and i can't move the character to control it as before nothing is working. Big mess.