Problem with player movement

Hello. The player I've created moves too fast, and it also seems to gain speed as it walks. The script I used is this:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class JugadorController : MonoBehaviour {
 
     
     private Rigidbody rb;
     
     private int contador;
     
     public Text textoContador, textoGanar;
 
     public float turnSpeed = 10f;
 
 
     
     public float velocidad;
 
 
     Animator m_Animator;
     Rigidbody m_Rigidbody;
     Vector3 m_Movement;
     Quaternion m_Rotation = Quaternion.identity;
 
     // Use this for initialization
     void Start () {
         
         
         rb = GetComponent<Rigidbody>();
         
         contador = 0;
 
         setTextoContador();
 
         textoGanar.text = "";
 
         m_Animator = GetComponent<Animator> ();
         m_Rigidbody = GetComponent<Rigidbody> ();
 
     }
     
     
     void FixedUpdate () {
         
         
         float movimientoH = Input.GetAxis("Horizontal");
         float movimientoV = Input.GetAxis("Vertical");
 
         
         Vector3 movimiento = new Vector3(movimientoH, 0.0f, movimientoV);
 
         
         rb.AddForce(movimiento * velocidad);
 
         float horizontal = Input.GetAxis ("Horizontal");
         float vertical = Input.GetAxis ("Vertical");
         
         m_Movement.Set(horizontal, 0f, vertical);
         m_Movement.Normalize ();
 
         bool hasHorizontalInput = !Mathf.Approximately (horizontal, 0f);
         bool hasVerticalInput = !Mathf.Approximately (vertical, 0f);
         bool isWalking = hasHorizontalInput || hasVerticalInput;
         m_Animator.SetBool ("IsWalking", isWalking);
 
         Vector3 desiredForward = Vector3.RotateTowards (transform.forward, m_Movement, turnSpeed * Time.deltaTime, 0f);
         m_Rotation = Quaternion.LookRotation (desiredForward);
 
     }
 
     
     void OnTriggerEnter(Collider other) 
     {
         if (other.gameObject.CompareTag ("Coleccionable"))
         {
             
             other.gameObject.SetActive (false);
                         contador = contador + 1;
             
             setTextoContador();
         }
     }
 
     
     void setTextoContador(){
 
         textoContador.text = "Contador: " + contador.ToString();
         if (contador >= 5){
             textoGanar.text = "You won";
         }
     }
 
     void OnAnimatorMove ()
     {
         m_Rigidbody.MovePosition (m_Rigidbody.position + m_Movement * m_Animator.deltaPosition.magnitude);
         m_Rigidbody.MoveRotation (m_Rotation);
     }
 }

What might be the problem??