Unable to edit fields from custom inspector

Hey everyone,

I was trying to organize my item system via a custom inspector. I have never used custom editors before, and may have made an amateur mistake :(

The script is making fields show up in the custom inspector, as expected, but when I try to edit the fields, they will no change. I will select a new value for my enum, but the inspector won't assign it. I can't assign game objects to my Object fields either and the float field is stuck at zero. Any advice is appreciated.

Here is the MonoBehaviour script that the editor script references:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public enum ItemClass{ Weapon, Armor, Consumable }
 
 public class ItemIndex : MonoBehaviour
 {
 
     
     public List<GameObject> item;
     public List<float> armor;
     public List<float> damage;
     public List<ItemClass> itemType;
 }  

Here is the editor script that creates the faulty fields:

 using UnityEditor;
 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 [CustomEditor(typeof(ItemIndex))]
 public class ItemIndexEditor : Editor {
 
     public override void OnInspectorGUI()
     {
         ItemIndex index = (ItemIndex)target;
         
         int totalItems = 0;
         
         GameObject currentPrefab = null;
         float currentArmor = 0;
         float currentDamage = 0;
         ItemClass currentItemType = ItemClass.Weapon;
         
         currentPrefab = (GameObject)EditorGUILayout.ObjectField("Item Prefab", currentPrefab, typeof(GameObject), false);
         currentItemType = (ItemClass)EditorGUILayout.EnumPopup("Item Type", currentItemType);
         
         if(currentItemType == ItemClass.Weapon)
         {
             currentDamage = EditorGUILayout.FloatField("Damage", currentDamage);
         }
         else if(currentItemType == ItemClass.Armor)
         {
             currentArmor = EditorGUILayout.FloatField("Armor", currentArmor);
         }
         
         
         if(GUILayout.Button("Create Item"))
         {
             totalItems += 1;
             index.item.Add(currentPrefab);
             index.itemType.Add(currentItemType);
         }
         
         
     }
 }
 

The editor script obviously isn't finished, but I would like to fix the fields, before completing the rest of the script. Thanks for any help.