Character controls broken due to mouse looking script

EDIT: SOLVED After removing the Box Collider from the Player object, the issue is gone

I'm following a youtube series on how to create a top-down shooter. The tutorials use c#, and to teach myself to script better I've been re-writing it in JS.

The problem is that when I try and move around, the character moves seemingly randomly all over the place. Here's my code:

 #pragma strict
 
 @script RequireComponent(CharacterController);
 
 //Components
 var controller : CharacterController;
 var cam : Camera;
 
 //System
 var motion : Vector3;
 var input : Vector3;
 var targetRotation : Quaternion;
 var mousePos : Vector3;
 
 //Handling
 var rotationSpeed : float = 450;
 var walkSpeed : float = 5;
 var runSpeed : float = 8;
 
 function Start()
 {
     cam = Camera.main;
 }
 
 function Update()
 {
     mousePos = Input.mousePosition;
     mousePos = cam.ScreenToWorldPoint(Vector3(mousePos.x,mousePos.y,cam.transform.position.y - transform.position.y));
     targetRotation = Quaternion.LookRotation(mousePos - Vector3(transform.position.x,0,transform.position.z));
     transform.eulerAngles = Vector3.up * Mathf.MoveTowardsAngle(transform.eulerAngles.y,targetRotation.eulerAngles.y, rotationSpeed * Time.deltaTime);
     
     input = Vector3(Input.GetAxisRaw("Horizontal"),0,Input.GetAxisRaw("Vertical"));
     motion = input;
     motion *= (Mathf.Abs(input.x) == 1 && Mathf.Abs(input.z) == 1)?.7f:1;
     motion *= (Input.GetButton("Run"))?runSpeed:walkSpeed;
     motion += Vector3.up * -8;
     controller.Move(motion * Time.deltaTime);
 }