How to destroy Instantiated objects (C#)(not last instantiated one)

Hello!I have a problem with my project. In global I'm trying to recreate something like Terraria or Starbound(just for fun) and currently I can place blocks while pressing mouse0 but how do I destroy objects when I press on them with mouse0.Currently I have place/destroy code in one script:

using UnityEngine;

using System.Collections;

public class Place : MonoBehaviour {

public GameObject Block;

private GameObject instantiatedObj;

  // Use this for initialization
 void Start () {
 
 }
 
 // Update is called once per frame
 void Update () {
     if(Input.GetMouseButton(0)){
         Vector2 mousePos = camera.ScreenToWorldPoint(new Vector2(Input.mousePosition.x,Input.mousePosition.y));
         instantiatedObj = (GameObject)Instantiate(Block, mousePos ,Quaternion.identity);
     }
         if(Input.GetMouseButton(1)){
         //works only for last instantiated obj
         Destroy(instantiatedObj);
         
         }
     
     
     
     
 }

}

The destroy function is working only for the last instantiated obj and I need it to work for all instantiated objects.Please help me!