Send me an Email if someone has made a change to my file.

[wherdzik]

I have a very sensitive file that I would like it to send me an email if someone has opened it or has has made a change to it. Is this possible? and if it is, is it a resource killer?
I found this code online, can it be modified for workbook?

Private Sub Worksheet_Change(ByVal Target As Range)
'Updated by Extendoffice 2017/9/12
    Dim xRgSel As Range
    Dim xOutApp As Object
    Dim xMailItem As Object
    Dim xMailBody As String
    On Error Resume Next
    Application.ScreenUpdating = False
    Application.DisplayAlerts = False
    Set xRg = Range("A2:E11")
    Set xRgSel = Intersect(Target, xRg)
    ActiveWorkbook.Save
    If Not xRgSel Is Nothing Then
        Set xOutApp = CreateObject("Outlook.Application")
        Set xMailItem = xOutApp.CreateItem(0)
        xMailBody = "Cell(s) " & xRgSel.Address(False, False) & _
            " in the worksheet '" & Me.Name & "' were modified on " & _
            Format$(Now, "mm/dd/yyyy") & " at " & Format$(Now, "hh:mm:ss") & _
            " by " & Environ$("username") & "."
 
        With xMailItem
            .To = "Email Address"
            .Subject = "Worksheet modified in " & ThisWorkbook.FullName
            .Body = xMailBody
            .Attachments.Add (ThisWorkbook.FullName)
            .Display
        End With
        Set xRgSel = Nothing
        Set xOutApp = Nothing
        Set xMailItem = Nothing
    End If
    Application.DisplayAlerts = True
    Application.ScreenUpdating = True
End Sub