Unity выдаёт ошибку

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.SceneManagement;
using TMPro;

public class LevelControl : MonoBehaviour
{
    public TextMeshPro text;
    private Timer NewTimer;

    // Start is called before the first frame update
    void Start()
    { 
        NewTimer = new Timer(10);
        NewTimer.Go();
    }

    // Update is called once per frame
    void Update()
    {
        text.text = NewTimer.Time().ToString();
    }
}


public class Timer : MonoBehaviour
{
    private int timer;

    public Timer(int n)
    {
        timer = n;
    }

    public void Go()
    {
        StartCoroutine(TimerStart());
    }
    private IEnumerator TimerStart()
    {
        if (timer > 0)
        {
            timer -= 1;
            yield return new WaitForSeconds(1);
            StartCoroutine(TimerStart());
        }
    }
    public bool CheckStop()
    {
        if (timer == 0)
        {
            return true;
        }
        return false;
    }
    public int Time()
    {
        return timer;
    }
}

Я создал вот такой код для таймера в своей игре. В visual studio нет ошибок, однако при запуске появляются предупреждение и ошибка:

You are trying to create a MonoBehaviour using the 'new' keyword.  This is not allowed.  MonoBehaviours can only be added using AddComponent(). Alternatively, your script can inherit from ScriptableObject or no base class at all
UnityEngine.MonoBehaviour:.ctor ()
Timer:.ctor (int) (at Assets/Scripts/LevelControl.cs:226)
LevelControl:Start () (at Assets/Scripts/LevelControl.cs:40)

NullReferenceException
UnityEngine.MonoBehaviour.StartCoroutine (System.Collections.IEnumerator routine) (at <42a5878ce129403083acccf18e43363f>:0)
Timer.Go () (at Assets/Scripts/LevelControl.cs:233)
LevelControl.Start () (at Assets/Scripts/LevelControl.cs:41)

В переменную text я через инспектор прикрепил TextMeshPro