[2D] problem with character persistence and respawn (dontdestroyonload singleton)

Hello everyone, I am a total beginner with Unity 3D so bear with me :)

I am trying to develop a small 2D platformer game. My problem is with my character's respawn. I have a killzone that reloads the level :

 using System;
 using UnityEngine;
 
 namespace UnityStandardAssets._2D
 {
     public class Restarter : MonoBehaviour
     {
         private void OnTriggerEnter2D(Collider2D other)
         {
             if (other.tag == "Player")
             {
                 Application.LoadLevel(Application.loadedLevelName);
             }
         }
     }
 }
 

With this when my character died, the level would reload just fine. But when I added a level 2, of course my character didn't persist. After a few researches I added a JS script on the character with a singleton pattern to keep my character between levels and preventing it from duplicating when respawning Here is my DontDestroyOnLoad js :

 static var created = false;
  
  function Awake() {
      if (!created) {
          // this is the first instance - make it persist
          DontDestroyOnLoad(transform.root.gameObject);
          created = true;
          
      } else {
          // this must be a duplicate from a scene reload - DESTROY!
          Destroy(transform.root.gameObject);
      } 
  }

Now if I enter the killzone, in the hierarchy i can see characters objects being created then deleted so that there is only 1 left. That is good, but apparently the level is not reloading and my character keeps falling down.

Does anyone see what I did wrong?

Please tell me if my explanation wasn't clear enough. Any help would be appreciated. Thanks !