what happened to my script

Please used code-tags . Huge walls of plain-text isn’t something anyone is going to read.

I’m kind of amazed you just cannot see the problem here on the line it tells you:

public class PlayerMovement : MonoBehaviour
// Some stupid rigidbody based movement by Dani

using System;
using UnityEngine;

public class PlayerMovement : MonoBehaviour
{

Copy/paste error.