Converting your code to VBA (second part where you add 'essais' text) I would have this one:
With CC.Range.Characters.Last
.InsertParagraphAfter
.Move wdParagraph '!!!!!!!!!
.Style = "Nagłówek 1"
.Text = "essais"
End With
As you can see I've added one line with '!!!! comment
moving insertion point to next paragraph which was add with .InsertParagraphAfter method
.