Assets/health.cs(11,23): error CS1519: Unexpected symbol `=' in class, struct, or interface member declaration

Unexpected symbol `=’ in class, struct, or interface member declaration
Where have i gone wrong?
here’s my code

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;

public class health : MonoBehaviour {
	public Slider healthbarslider;
	public Text gameOverText;

	gameOverText.enabled = false;
	void OnCollisionEnter(Collision col)
	{
		if (col.gameObject.name == "object")
		{
			healthbarslider.value -= 10f;
		}
		if (healthbarslider.value == 0) 
		{
			gameOverText.enabled == true;
			System.Threading.Thread.Sleep (5000);
			Application.LoadLevelAsync(Application.loadedLevelName);
		}

	}
}

@c4k3m45t3r These seems to work for me not much was changed compared to your code.

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

public class Health : MonoBehaviour
{
    [Header("References")]
    public Slider healthbarslider;
    public Text gameOverText;

    // Use this for initialization
    void Start()
    {
        gameOverText.enabled = false;
        healthbarslider.GetComponent<Slider>();
    }

    void OnCollisionEnter(Collision col)
    {
        if (col.gameObject.name == "object")
        {
            healthbarslider.value -= 10f;
        }
        if (healthbarslider.value <= 0)
        {
            gameOverText.enabled = true;
            //System.Threading.Thread.Sleep(5000);
            // Will load level 0 change this to ur level int id u need.
            SceneManager.LoadSceneAsync(0);
        }
    }
}