Auto-Center 3rd person camera, problem when moving towards the camera

I've made myself a 3rd person camera control object for a retro platformer game, standard WASD movement and UDLR view.

but I'm trying to add an auto center (of which will be toggle-able and adjustable in the options) but when the player walks towards the camera (via. S) the camera jerks back and forth, all other directions work fairly well, sometimes a tiny jitter when moving tot he left, but nothing horrific.

I'm not sure how I should fix this and help would be greatly appreciated, Here is the Camera control script, I keep most variables in public classes so their organised in the inspector.

     using UnityEngine;
 using System;
 using System.Collections;
 using System.Collections.Generic;
 
 public class ThirdPersonCameraScript : MonoBehaviour {
 
  [Serializable]
  public class ViewInformation
  {
  [Serializable]
  public class Offset
  {
  public Vector3 positionOffset = new Vector3(0,0,0);
  public Vector3 rotationOffset = new Vector3(0,0,0);
  public Vector3 directionOffset = new Vector3(0,0,0);
  }
  [Serializable]
  public class Follow
  {
  public float followWeight = 0;
  }
  [Serializable]
  public class Speed
  {
  public float horizontalAccel = 3;
  public float horizontalSpeed = 6;
  public float verticalAccel = 3;
  public float verticalSpeed = 6;
  public float dampening = 0.2f;
  }
  public Offset offset;
  public Follow follow;
  public Speed speed;
  }
  float horizontalSpeed = 0;
  float verticalSpeed = 0;
  
  public ViewInformation view;
  protected Transform targetTransform;
  
  void Start () {
  
  }
  public void InitiateCamera(Transform _playerTransform)
  {
  targetTransform = _playerTransform;
  }
  
  void View()
  {
  Vector3 input = new Vector3(Input.GetAxis("VerticalView"), Input.GetAxis("HorizontalView"), 0);
  if (input.y != 0)
  {
  horizontalSpeed += view.speed.horizontalAccel;
  if (horizontalSpeed > view.speed.horizontalSpeed) horizontalSpeed = view.speed.horizontalSpeed;
  }
  else
  {
  horizontalSpeed -= view.speed.horizontalAccel;
  if (horizontalSpeed < 0) horizontalSpeed = 0;
  }
  
  if (input.x != 0)
  {
  verticalSpeed += view.speed.verticalAccel;
  if (verticalSpeed > view.speed.verticalSpeed) verticalSpeed = view.speed.verticalSpeed;
  }
  else
  {
  verticalSpeed -= view.speed.verticalAccel;
  if (verticalSpeed < 0) verticalSpeed = 0;
  }
  
  Vector3 direction = transform.eulerAngles;
  input.y *= horizontalSpeed;
  input.x *= verticalSpeed;
  direction += input;
  if (direction.x < 270 && direction.x > 60) direction.x = 60;
  if (direction.x < 280 && direction.x > 90) direction.x = 280;
  direction = Vector3.Lerp(direction, targetTransform.eulerAngles, view.follow.followWeight);
  transform.eulerAngles = direction;
  
  Vector3 cameraTarget = targetTransform.position + view.offset.positionOffset;
  cameraTarget += transform.rotation * view.offset.rotationOffset;
  
  transform.position = Vector3.Lerp(transform.position, cameraTarget, view.speed.dampening);
  }
  
  void FixedUpdate () {
  View ();
  }
 }

Any and all help is greatly appreciated, thanks in advanced,

Bombshell