My script to kill the player and respawn, does nothing?

I've been trying to get answers from on here for a day or 2 now, and I cannot seem to find one. Each answer = new question. I think I am getting closer, before I had an error, now it just doesn't do anything. (I probably did something stupid somewhere) I am very new to coding, so don't expect me to understand a lot (Do you know any good tutorial series?). I basically want to get rid of the PlayerMovement, and then 2 seconds later get rid of Mesh, BoxCollider, if Health <= 0, (In case it goes negative or something). And then, after five seconds, I want all three of those to come back. And then, Health = 100. I thought I had the code right, but when health = 0, nothing happens. Thanks in advance for the help (And possibly a good series to watch on youtube for c# coding)

Here is the script:

 using UnityEngine;
 using System.Collections;
 
 public class AttributeDeclaration : MonoBehaviour {
     #region Public ints
     public int Health = 100;
     public int Magic = 100;
     public int Strength = 100;
     public int Stamina = 100;
     public int Defense = 100;
 
     //Maximum attributes
     public int MaxHealth = 100;
     public int MaxMagic = 100;
     public int MaxStrength = 100;
     public int MaxStamina = 100;
     public int MaxDefense = 100;
 
     //Testing Stuff
     public int DamageAmount = 20;
 
     //---------------------------------------------------------------------------------------------
     #endregion
 
     public PlayerLevelDeclaration PT;
     public PlayerMovement PM;
     public HealthPotion HP;
 
     //----------------------------------------------------------------------------------------
     void Awake(){
         newPos = transform.position;
     }
     //-------------------------
     // Use this for initialization
     void Start () {
     }
     //-----------------------------------------------------------------------------------------
     // Update is called once per frame
     void Update () {
         PT = gameObject.GetComponent<PlayerLevelDeclaration>();
         HP = gameObject.GetComponent<HealthPotion>();
         PM = gameObject.GetComponent<PlayerMovement>();
 
         TempDamageHealth();
         TempDamageStamina();
         TempDamageMagic();
         TempDamageStrength();
         TempDamageDefense();
 
         DisallowNegative();
 
         KillPlayer();
     }
     //----------------------------------------------------------------------------------------
     void DisallowNegative(){
         if(Health <= 0)
         {
             Health = 0;
         }
         if(Stamina <= 0)
         {
             Stamina = 0;
         }
         if(Magic <= 0)
         {
             Magic = 0;
         }
         if(Strength <= 0)
         {
             Strength = 0;
         }
         if(Defense <=0)
         {
             Defense = 0;
         }
     }
     //-----------------------------------------------------------------------------------------
 
     public int TempDamageHealth()
     {
 
         if(Input.GetKeyDown(KeyCode.Keypad1))
         {
             Health = Health - DamageAmount;
         }
         return Health;
     }
     //-------------------------------------------------------------------------------------
     public int TempDamageStamina()
     {
         
         if(Input.GetKeyDown(KeyCode.Keypad2))
         {
             Stamina = Stamina - DamageAmount;
         }
         return     Stamina;
     }
     //--------------------------------------------------------------------------------------
     public int TempDamageMagic()
     {
         
         if(Input.GetKeyDown(KeyCode.Keypad3))
         {
             Magic = Magic - DamageAmount;
         }
         return Magic;
     }
     //------------------------------------------------------------------------------------------
     public int TempDamageStrength()
     {
         
         if(Input.GetKeyDown(KeyCode.Keypad4))
         {
             Strength = Strength - DamageAmount;
         }
         return Strength;
     }
     //----------------------------------------------------------------------------------
     public int TempDamageDefense()
     {
         
         if(Input.GetKeyDown(KeyCode.Keypad9))
         {
             Defense = Defense - DamageAmount;
         }
         return Defense;
     }
 //--------------------------------------------------------------------
     Vector3 newPos;
     bool IsAlive = true;
     IEnumerator KillPlayer(){
     if(Health <= 0)
         {
             IsAlive = false;
             Health = 0;
             //Hopefully this makes it so the player can't move as soon as Health = 0, but doesn't disappear and lose 
             //collision until after 2 seconds. Then, 5 seconds later, the player's position is set to 0, 0, 0, and 
             //He regains movement, reappears, and regains collision.
 
             //Kill Player
             PM.enabled = false;
             yield return new WaitForSeconds(2f);
             renderer.enabled = false;
             collider.enabled = false;
             PM.enabled = false;
                     
             //Wait 5 seconds
             yield return new WaitForSeconds(5f);
 
             //Set position code;
             Vector3 PlayerSpawn = new Vector3(0f , 0f , 0f);
             newPos = PlayerSpawn;
             transform.position = newPos;
             //Rest
             renderer.enabled = true;
             collider.enabled = true;
             PM.enabled = true;
             IsAlive = true;
             Health = MaxHealth;
 
 
         }
         yield return IsAlive == true;
     }
 
 }