Copying sheets and updating values from a main sheet

Hi guys,

I have a sheet 'matrix' which has a list of names across the row 2.
They each then have a list of values.
I'm trying to make a macro that will create a new sheet for each of the names based on a template and then add the values with the date it was run at the top. Then when run again it should add another column with the date at the top and only show values that have been changed.

So far creating the sheets works fine. Adding the values was working but seems to have broken and now I'm stuck. Sometimes it seems to work correctly, other times there will be values and no dates, sometimes all of the values rather than just those that have changed.

Please can anyone offer any advice?

Code:

---

Sub Macro2()
'
' Macro2 Macro
'
' 
Dim nextCol As Long, firstRow As Long, lastRow As Long, lastVal As Long
Dim n As Variant, nm As Variant, nms As Variant

Const m = "Matrix"

Dim d As String

    d = Date

    Set nms = Sheets(m).Range("E2", Sheets(m).Range("E2").End(xlToRight)) ' Set range as names

    For Each nm In nms
        If DoesSheetExists(nm.Value) Then
        Else
          Sheets("Template").Copy After:=Sheets(Sheets.Count) 'Copies the template worksheet
          Sheets(Sheets.Count).Name = nm.Value ' renames the new worksheet
      End If
  Next nm
       
    with Sheets(m)
        nms = Application.WorksheetFunction.Transpose(nms)
  End With

  For Each nm In nms ' loop through names
      n = Application.WorksheetFunction.Match(nm, Sheets(m).Range("2:2"), 0) ' find the column this name appears in on the matrix
   
      'enter changes on the individual sheet
      With Sheets(nm)
          nextCol = .Cells(2, 1) ' get column number for entries
          lastRow = .Range("C" & .Rows.Count).End(xlUp).Row 'last row of tasks
               
          For firstRow = 3 To lastRow
            lastVal = Cells(firstRow, Columns.Count).End(xlToLeft).Column ' locate last column with an entry
            If .Cells(firstRow, lastVal) = Sheets(m).Cells(firstRow, n) Then  ' if the last value matches the value in the matrix
            Else: .Cells(firstRow, nextCol) = Sheets(m).Cells(firstRow, n) ' add the value ot the next empty column
            End If
        Next firstRow
                   
        If Application.WorksheetFunction.Sum(Columns(nextCol)) = 0 Then
        Else
            .Cells(2, nextCol) = d
        End If
    End With
  Next nm
End Sub


Function DoesSheetExists(sh As String) As Boolean
    Dim ws As Worksheet

    On Error Resume Next
      Set ws = ThisWorkbook.Sheets(sh)
    On Error GoTo 0

    If Not ws Is Nothing Then DoesSheetExists = True
End Function

---

I'm sorry, I just can't keep my brain straight reading the code when I must keep going back to determine what d,m,n,nm,nms,and xyz refer to.

There is a reason why Best Practices insists on using meaningful variable names. It's for simple minds like mine.

Not to worry, Paul will probably respond next, and he is sharp.