Oh, look at me, I figured it out! For those curious,

I replaced:

 Selection.AutoFill Destination:=Range("F2:F33")
    Range("F2:F33").Select

With this:

LastRow = Range("A1").End(xlDown).Row ' Ctrl+Down from cell A1
Range("F2").AutoFill Destination:=Range("F2:F" & LastRow)
Range("F1").AutoFilter