Trying to make a third person camera, whats wrong with this transform.position?

im trying to make it so that if the mouse is moved up, the camera moves back, moves down, and rotates up. and the opposite when the mouse moves down. This variable is applied to the localposition:

 CameraPos = new Vector3 (transform.localPosition.x, Mathf.Clamp (CameraPos.y + (MouseY - MouseYSet) * Sensitivity * 10, CameraTarget.transform.position.y + CameraTarget.transform.localScale.y / 2, CameraTarget.transform.position.y + CameraTarget.transform.localScale.y / 2 + MaxPos), Mathf.Clamp (CameraPos.z + (MouseY - MouseYSet) * Sensitivity * 10, CameraTarget.transform.position.z - MaxPos, CameraTarget.transform.position.z));

try making a player, making the camera a child, and applying this script to the camera:

 using UnityEngine;
 using System.Collections;
 
 public class CameraController : MonoBehaviour {
     
     public float Sensitivity;
     public float MaxPos;
     public float MaxAngle;
     private float MouseY;
     private float MouseYSet;
     private float CameraAngle;
 
     private Vector3 CameraPos;
 
     public GameObject CameraTarget;
     
     void Start () {
         
     }
     
     void Update () {
         // Rotation controls
         MouseY -= Input.GetAxisRaw ("Mouse Y");
         CameraAngle = Mathf.Clamp (CameraAngle + (MouseY - MouseYSet) * Sensitivity * 10, -MaxAngle, MaxAngle);
         CameraPos = new Vector3 (transform.localPosition.x, Mathf.Clamp (CameraPos.y + (MouseY - MouseYSet) * Sensitivity * 10, CameraTarget.transform.position.y + CameraTarget.transform.localScale.y / 2, CameraTarget.transform.position.y + CameraTarget.transform.localScale.y / 2 + MaxPos), Mathf.Clamp (CameraPos.z + (MouseY - MouseYSet) * Sensitivity * 10, CameraTarget.transform.position.z - MaxPos, CameraTarget.transform.position.z));
         if (MouseY != 0)
         {
             transform.localRotation = Quaternion.Euler (CameraAngle, 0, 0);
             transform.localPosition = new Vector3 (0, CameraPos.y, CameraPos.z);
             MouseYSet = MouseY;
         }
     }
 }

and this to the player:

 using UnityEngine;
 using System.Collections;
 
 public class PlayerController : MonoBehaviour {
 
     public int Speed;
     public int RunSpeed;
     public int Sensitivity;
     public int JumpHeight;
     public int Force;
 
     private float TerrainHeight;
     private float TerrainHeightSet;
     private float PlayerFoot;
     private float MouseX;
     private float MouseXSet;
 
     private bool Jumping;
     private bool Running;
 
     void Start () {
         Jumping = false;
         Running = false;
     }
 
     void Update () {
         PlayerFoot = transform.position.y - transform.lossyScale.y / 2;
         TerrainHeight = Terrain.activeTerrain.SampleHeight (transform.position);
 
         // Translation controls
         if (Input.GetKey (KeyCode.W) && Running == false)
         {
             transform.position += transform.forward * Speed * 20 * Time.deltaTime;
         }
         if (Input.GetKey (KeyCode.S) && Running == false)
         {
             transform.position -= transform.forward * Speed * 20 * Time.deltaTime;
         }
         if (Input.GetKey (KeyCode.D) && Running == false)
         {
             transform.position += transform.right * Speed * 20 * Time.deltaTime;
         }
         if (Input.GetKey (KeyCode.A) && Running == false)
         {
             transform.position -= transform.right * Speed * 20 * Time.deltaTime;
         }
 
         // Run controls
         if (Input.GetKey (KeyCode.W) && Input.GetKey (KeyCode.Q))
         {
             Running = true;
         }
         if (Input.GetKey (KeyCode.W) && Running == true)
         {
             transform.position += transform.forward * RunSpeed * 20 * Time.deltaTime;
         }
         if (Input.GetKeyUp (KeyCode.Q) && Input.GetKeyUp (KeyCode.W))
         {
             Running = false;
         }
 
         // Rotation controls
         MouseX += Input.GetAxisRaw ("Mouse X");
 
         if (MouseXSet != MouseX)
         {
             transform.Rotate (new Vector3 (0,(MouseX - MouseXSet) * Sensitivity * 10, 0));
             MouseXSet = MouseX;
         }
 
         // Jump controls
         if (Input.GetKey (KeyCode.Space) && PlayerFoot < TerrainHeight + 1 && PlayerFoot < TerrainHeight + JumpHeight * 10)
         {
             TerrainHeightSet = TerrainHeight;
             StartCoroutine (JumpDelay ());
         }
         if (Jumping == true)
         {
             rigidbody.velocity = new Vector3 (0, (Force * 10), 0);
         }
         if (Input.GetKeyUp (KeyCode.Space))
         {
             Jumping = false;
         }
         if (PlayerFoot >= TerrainHeightSet + JumpHeight * 10)
         {
             Jumping = false;
         }
         if (Jumping == false)
         {
             rigidbody.velocity = new Vector3 (0, -(Force * 20), 0);
         }
 
         // Keep player upright
         if (PlayerFoot < TerrainHeight + 1)
         {
             transform.position += Vector3.up * (TerrainHeight - PlayerFoot);
         }
     }
 
     // Check if player really wants to jump
     IEnumerator JumpDelay () {
         yield return new WaitForSeconds (0.05f);
         if (Input.GetKey (KeyCode.Space))
         {
             Jumping = true;
         }
         StopCoroutine (JumpDelay ());
     }
 }