Menu controller script not working

This C# script is driving me insane. I have script which controls prefabs and, sprites, and index locations for my menus. When you press a panel button, a submenu opens up, and a menu corresponding to the pressed panel is set as a child to the parent. The problem is, you could press buttons in any order, so I have something set up where there are different tabs open for every sublevel, and the different menus can be set as a child to any of the sublevels.

When closing the sublevels, however, everything messes up. Random sublevels are left up, some icons which depict the open menu don't change properly, and I'm left feeling hollow and empty inside. For a week I've tried fixing it, and I've almost come to the sad realization that this isn't even necessary, and I could replace this code with something much simpler and it wouldn't matter. Here's the code:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.UI;
5.  
6. public class MenuController : MonoBehaviour {
7.  
8.     //Different icons of menu sprites that go on top, on the tabs --By index--
9.     public Sprite[] icons = new Sprite[6];
10.  
11.     //Information of menus, inventory, stats, etc. --By index--
12.     public GameObject[] menus = new GameObject[6];
13.  
14.     //Information on the submenues, the ones with the tabs --By windowsUp--
15.     public GameObject[] subMenus = new GameObject[6];
16.  
17.     //Location of image componenents in submenus --By windowsUp--
18.     public GameObject[] imgs = new GameObject[6];
19.  
20.     //I set the menu information back to this when closing the menus
21.     public GameObject parentIcon;
22.  
23.     //Used so I can control the "Interactable", which moves the UIbox
24.     public Animator parentAnimator;
25.  
26.     //Which submenu the menu is in --By index--
27.     int[] location = new int[6];
28.  
29.     //Which index the current submenu is using --By windowsUp--
30.     int[] indexLoc = new int[6];
31.  
32.     //If the menu is already up --By index--
33.     bool[] isUsed = new bool[7];
34.  
35.     //Which menu is used
36.     int windowsUp = 0;
37.    
38.     void Awake()
39.     {
40.         isUsed[6] = false;
41.     }
42.  
43.     public void AddMenu (int index)
44.     {
45.         if (!isUsed[index])
46.         {
47.             //Stops player from moving
48.             FindObjectOfType<PlayerMovement>().canMove = false;
49.  
50.             //Stops playing from scanning
51.             FindObjectOfType<PlayerScanner>().canScan = false;
52.  
53.             //Stops UIbox from moving too much
54.             parentAnimator.SetBool("interactable", false);
55.  
56.  
57.             //Moves the subwindow to the front
58.             subMenus[windowsUp].transform.SetAsLastSibling();
59.  
60.             //Sets the submenu's tab icon as what menu is being opened
61.             imgs[windowsUp].GetComponent<Image>().sprite = icons[index];
62.  
63.             //Sets the location of the specific menu
64.             location[index] = windowsUp;
65.  
66.             //Sets the index to whatever window is up
67.             indexLoc[windowsUp] = index;
68.  
69.             //Makes the menu information be a child to the submenu, so it hides when another submenu is focused on
70.             menus[index].transform.SetParent(subMenus[windowsUp].transform);
71.  
72.             //Turns on the menu so it can be seen
73.             menus[index].SetActive(true);
74.  
75.             //Turns on the sub menu so it can be seen
76.             subMenus[windowsUp].SetActive(true);
77.  
78.             //Makes it so we can't open another copy of the same menu
79.             isUsed[index] = true;
80.  
81.             //Incremented for the next possible opened window
82.             windowsUp++;
83.         }else
84.         {
85.             //Menu is already up, we are just focusing on it
86.             subMenus[location[index]].transform.SetAsLastSibling();
87.         }
88.     }
89.  
90.     public void FocusMenu(GameObject submenu)
91.     {
92.         submenu.transform.SetAsLastSibling();
93.     }
94.  
95.     public void RemoveMenu(int index)
96.     {
97.         //If this is in the first slot, and the window next to it isn't up
98.         if (location[index] == 0 && !isUsed[ indexLoc[ location[index] + 1] ])
99.         {
100.             //Set the last menu as a child under the child manager
101.             menus[index].transform.SetParent(parentIcon.transform);
102.  
103.             //Hides the submenu
104.             subMenus[0].SetActive(false);
105.  
106.             //Hides the menu
107.             menus[index].SetActive(false);
108.  
109.             //The menu isn't being used any more
110.             isUsed[index] = false;
111.  
112.             //There aren't any more windows up
113.             windowsUp = 0;
114.  
115.             FindObjectOfType<PlayerMovement>().canMove = true;
116.             FindObjectOfType<PlayerScanner>().canScan = true;
117.             parentAnimator.SetBool("interactable", true);
118.         }else
119.         {
120.             //Sets the deleted menu to be under the menu controller parent
121.             menus[index].transform.SetParent(parentIcon.transform);
122.  
123.             //Disables the deleted menu
124.             menus[index].SetActive(false);
125.  
126.             //Disables the deleted submenu
127.             subMenus[location[index]].SetActive(false);
128.  
129.             //This window isn't being used anymore
130.             isUsed[index] = false;
131.  
132.             //For each submenu after the one we're removing
133.             for(int i = location[index]; i < 6; i++)
134.             {
135.                 //If the window right after our window isn't being used (the window we're closing is the last window)
136.                 if (i == 5 || !isUsed[indexLoc[i + 1]])
137.                 {
138.                     //Sets the submenu before it in front of all the other submenus
139.                     if(i == location[index] && subMenus[i - 1] != null) { subMenus[i - 1].transform.SetAsLastSibling(); }
140.  
141.                     //Makes the menu be a parent to the window below it
142.                     menus[indexLoc[i]].transform.SetParent(subMenus[i - 1].transform);
143.  
144.                     //Fixes the icon of the submenu before it
145.                     imgs[i - 1].GetComponent<Image>().sprite = icons[indexLoc[i]];
146.  
147.                     //Enables the submenu before it
148.                     subMenus[i - 1].SetActive(true);
149.  
150.                     //Sets the current submenu as inactive
151.                     subMenus[i].SetActive(false);
152.  
153.                     //Updates the location
154.                     location[indexLoc[i]]--;
155.  
156.                     //Sets the index to new window
157.                     indexLoc[i - 1] = indexLoc[i];
158.  
159.                     //The latest open window is the one before the closed one now
160.                     //windowsUp = i - 1;
161.                     break;
162.                 }
163.                 //This isn't the last window
164.                 else if(!(i == location[index]) && isUsed[indexLoc[i]])
165.                 {
166.                     //Makes the menu be a parent to the window below it
167.                     menus[indexLoc[i]].transform.SetParent(subMenus[i - 1].transform);
168.  
169.                     //Fixes the icon of the submenu before it
170.                     imgs[i - 1].GetComponent<Image>().sprite = icons[indexLoc[i]];
171.  
172.                     //Enables the submenu before it
173.                     subMenus[i - 1].SetActive(true);
174.  
175.                     //Sets the current submenu as inactive
176.                     subMenus[i].SetActive(false);
177.  
178.                     //Updates the location
179.                     location[indexLoc[i]]--;
180.  
181.                     //Sets the index to new window
182.                     indexLoc[i - 1] = indexLoc[i];
183.                 }
184.  
185.                 //The latest open window is the one before the closed one now
186.                 windowsUp--;
187.             }
188. }
189. }
190. }