Need help in login vba code to unhide specific sheets depends on login info

Hello there,

Actually I have found this code and it does what I need but there's 1 problem that if you use a tool like kutools and click the option of unhide all sheets then all sheets will be hidden so what I need to add to the following code is when the username and password are correct in addition of visible the sheet which required the sheet to be unprotected so after visible the sheet I need to protect workbook structure again... so how I can perform that in the following code:

Private Sub Workbook_Open()
Dim Sh As Worksheet
Dim UserName As String
Dim Password As String
Dim ThisCell As Range
Dim c As Long
For Each Sh In ThisWorkbook.Worksheets
If ThisWorkbook.ProtectStructure = True Or ThisWorkbook.ProtectWindows = True Then ThisWorkbook.Unprotect WPwd
Sh.Activate
If Sh.Name <> "WELCOME SCREEN" Then
Sh.Visible = xlSheetVeryHidden
End If
Next Sh
UserName = InputBox("Please enter your user name.")
Password = InputBox("Please enter password.")
For Each ThisCell In Sheets("User List").Range("A2:A" & Sheets("User List").Range("A65536").End(xlUp).Row)
If UCase(ThisCell.Value) = UCase(UserName) And UCase(ThisCell.Offset(, 1).Value) = UCase(Password) Then
MsgBox "Access Granted"
For c = 2 To 4
'This is the number of sheets from C1 to E1
If ThisCell.Offset(, c).Value <> "" Then
Sheets(Sheets("User List").Cells(1, c + 1).Value).Visible = xlSheetVisible
End If
Next c
Exit Sub
End If
Next ThisCell
MsgBox "Access Denied"
ThisWorkbook.Close
End Sub

this code placed in THISWORKBOOK

the idea of the code is to create WELCOME SCREEN sheet and User List sheet which contain a table with username + password + sheet1 + sheet2 + .... as columns
under the sheet1, sheet2 I just insert "x" to let the sheet visible for the user or "" empty if I want the sheet to not be visible for the user, the only problem that the hidden sheet can be visible by kutools or maybe another tools when you click hide/unhide all sheets which make everything useless and weak.

Thanks in Advanced