Why isnt my Proc Gen dungeon working correctly

Question

I got the first room of my procedural dungeon working, or rather one room, however I dont know where to go from here to create multiple rooms as I cant just use CreateRoom again for some reason. If anyone could help I would appreciate it very much, Im new to coding so it's hard for me to understand why I cant use the same function while changing the starting position.

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

public class ProcGen : MonoBehaviour
{
    public GameObject[] floorTiles;
    public GameObject[] wallTiles;
    public float ceilingHeight;
     public Vector3 roomSpawn = new Vector2(0, 0);

    // Start is called before the first frame update
    void Start()
    {
        //Instantiate(floorTiles[0]);
        CreateRoom(Random.Range(2,7), Random.Range(2,9), roomSpawn);
        //CreateRoom(2,2, new Vector2(50, 50));
    }

    // Update is called once per frame
    void Update()
    {
    
    }

    void CreateRoom(int width, int length, Vector2 position)
    {
        // FLOOR and Roof GENERATION
        int tileWidth = (int)floorTiles[0].GetComponent<MeshRenderer>().bounds.size.x;
        // truncate the position that was passed in
        Vector2 firstPos = new Vector2(Mathf.Floor(position.x), Mathf.Floor(position.y));
        Vector2 tilePos = firstPos;
        
        for(int i = 0; i < width; i++)
        {
            for(int j = 0; j < length; j++)
            {
                Instantiate(floorTiles[Random.Range(0, floorTiles.Length)], new Vector3(tilePos.x, 0, tilePos.y), Quaternion.identity);
                Instantiate(floorTiles[0], new Vector3(tilePos.x, ceilingHeight, tilePos.y), Quaternion.Euler (0f, 0f, 180f));
                tilePos += new Vector2(tileWidth, 0);
            }
            tilePos = new Vector2(firstPos.x, tilePos.y);
            tilePos += new Vector2(0, tileWidth);
        }


        // WALL GENERATION
        float rotation = 90;
        
        Vector2 wallPos = firstPos;
        for(int i = 0; i < length; i++)
        {
            Instantiate(wallTiles[Random.Range(0, wallTiles.Length)], new Vector3(wallPos.x, 0, 0), Quaternion.Euler(new Vector3(0, rotation, 0)));
            wallPos += new Vector2(tileWidth, 0);
        }

        rotation += 90;
        for(int i = 0; i < width; i++)
        {
            Instantiate(wallTiles[Random.Range(0, wallTiles.Length)], new Vector3(0, 0, wallPos.y), Quaternion.Euler(new Vector3(0, rotation, 0)));
            wallPos += new Vector2(0, tileWidth);
        }

        rotation += 90;
        for(int i = 0; i < length; i++)
        {
            Instantiate(wallTiles[Random.Range(0, wallTiles.Length)], new Vector3(i * tileWidth, 0, firstPos.y + ((width - 1) * tileWidth)), Quaternion.Euler(new Vector3(0, rotation, 0)));
            wallPos += new Vector2(tileWidth, 0);
        }

        rotation += 90;
        for(int i = 0; i < width; i++)
        {
            Instantiate(wallTiles[Random.Range(0, wallTiles.Length)], new Vector3((length - 1) * tileWidth, 0, i * tileWidth), Quaternion.Euler(new Vector3(0, rotation, 0)));
            wallPos += new Vector2(0, tileWidth);
        }
    }

    int CalculateAddition(int left, int right)
    {
        return left + right;
    }
}

Like I said I tried to use CreateRoom again and it overlayed it on top of spawn again, but the walls didnt correctly place like I wanted them to, they seem to be placing at the spawn again.