Changing a Player's GameObject when damaged/powerup

Hi, I'm about 2 weeks into learning Unity and C# so bare with me.

I'm making a Mario clone so i can understand how this all works, and have been relying heavily on the 2D tutorial and some other resources on how this all works.

I've set up 2 separate game objects for mario, one big one small, in my code i'm using health to determine what version of mario appears.

 public GameObject marioHealth1;
 public GameObject marioHealth2;  

 void Start () 
 {
     anim = GetComponent<Animator> ();
     marioControl = GetComponent<MarioControls> ();

     
 }
 
 
 // Update is called once per frame
 void FixedUpdate () 
 {
             anim.SetBool ("Dead", isDead);
             if (health <= 0 && !isDead)
             {
                         Death ();
                         }
 
             if (health == 1)
             {    
             Instantiate (marioHealth1, gameObject.transform.position, gameObject.transform.rotation);
             Destroy (gameObject);
             
             }
     


 }

This works but i'm sure this isn't the way to do this, i noticed that the camera stops following the player which i'm assuming that's because i destroyed the game object and i'm positive theres going to be other issues as i get further into this.

what would be the best method to achieve this?