VBA Code "Next" button. Should be so simple...

Declare your variables at the top of the UserForm

Dim CurrentRow As Long   ' Keeps track of which record you are on
Dim LastRow As Long      ' Stores the last row of your data

Initialize the UserForm

Private Sub UserForm_Initialize()
    ' Find the last row of data in column A
    LastRow = Sheet1.Cells(Sheet1.Rows.Count, "A").End(xlUp).Row
    
    ' Start with the first record (row 5)
    CurrentRow = 5
    
    ' Load the first record into the form
    LoadRecord CurrentRow
End Sub

Next Button (CommandButton6)

Private Sub CommandButton6_Click()
    ' Debug: See current and last row in Immediate Window
    Debug.Print "CurrentRow=" & CurrentRow & " LastRow=" & LastRow
    
    ' Check if we are already at the last record
    If CurrentRow < LastRow Then
        ' Move to the next row
        CurrentRow = CurrentRow + 1
        
        ' Load the new record into the form
        LoadRecord CurrentRow
    Else
        ' If we are at the last record, show a message
        MsgBox "This is the last record."
    End If
End Sub

Prev Button (CommandButton7)

Private Sub CommandButton7_Click()
    ' Debug: See current and first row
    Debug.Print "CurrentRow=" & CurrentRow
    
    ' Check if we are already at the first record
    If CurrentRow > 5 Then
        ' Move to the previous row
        CurrentRow = CurrentRow - 1
        
        ' Load the new record into the form
        LoadRecord CurrentRow
    Else
        ' If we are at the first record, show a message
        MsgBox "This is the first record."
    End If
End Sub

LoadRecord Subroutine

You probably already have this, but just for clarity...

Sub LoadRecord(RowNumber As Long)
    ' Example: fill two textboxes from columns A and B
    TextBox1.Value = Sheet1.Cells(RowNumber, "A").Value
    TextBox2.Value = Sheet1.Cells(RowNumber, "B").Value
End Sub

UserForm opens → UserForm_Initialize sets CurrentRow = 5 and LastRow dynamically.

Clicking Next → increases CurrentRow until LastRow.

Clicking Prev → decreases CurrentRow until 5.

Messages appear if you try to go past first or last record.

My answers are voluntary and without guarantee!

Hope this will help you.