❔ Dictionary won't be larger than one

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Tilemaps;
using System;

public class Controls : MonoBehaviour
{   
    public class myResource {
        public string Name { get; set; }
        public int Amount { get; set; }
    }

    public Tilemap mainMap;
    public Tilemap objectMap;
    public Tilemap resourceMap;
    public TileBase testtile;
    // public Dictionary<Vector3Int, string> objectPlacements;
    // public Dictionary<Vector3Int, string> resource;

    public Dictionary<Vector3Int, myResource> tiles;

    private Rigidbody2D rb;
    public float speed = 10f;
    // Start is called before the first frame update
    void Start()
    {
        
        rb = GetComponent<Rigidbody2D>();
    }

    void Update()
    {
        if (Input.GetMouseButtonDown(0)) {
            resourceMap.SetTile(GetWorldCellPos(), testtile);
            tiles = new Dictionary<Vector3Int, myResource>();
            var tile = new myResource {
                Name = "copper",
                Amount = UnityEngine.Random.Range(1,10)
            };
            tiles.Add(GetWorldCellPos(), tile);
            Debug.Log(tiles[GetWorldCellPos()].Name);
            Debug.Log(tiles[GetWorldCellPos()].Amount);
        }
        if (Input.GetMouseButtonDown(1)) {
            if (tiles.ContainsKey(GetWorldCellPos())) {
                Debug.Log(tiles[GetWorldCellPos()].Name);
            Debug.Log(tiles[GetWorldCellPos()].Amount);
            }
            foreach (KeyValuePair<Vector3Int, myResource> item in tiles) {
                Debug.Log("Key: " + item.Key + " Value: " + item.Value);
            }
            Debug.Log(tiles.Count);
            
        }