Insert TextBox value into first empty cell in column

I have the following code which works fine. (TextBoxes are on "UserForm" in Excel VBA, and executes with clicking CommandButton1 on that UserForm.) But can anyone help me to insert the value of each TextBox into the first empty cell in Column M? This way inserts empty rows. I will use this in several workbooks, so using "ActiveSheet" is easiest for me.

Sub UserForm_Initialize()
Me.TextBox1.Value = CStr(ActiveSheet.Range("M1").Value)
Me.TextBox2.Value = CStr(ActiveSheet.Range("M2").Value)
Me.TextBox3.Value = CStr(ActiveSheet.Range("M3").Value)
Me.TextBox4.Value = CStr(ActiveSheet.Range("M4").Value)
Me.TextBox5.Value = CStr(ActiveSheet.Range("M5").Value)
Me.TextBox6.Value = CStr(ActiveSheet.Range("M6").Value)
Me.TextBox7.Value = CStr(ActiveSheet.Range("M7").Value)
Me.TextBox8.Value = CStr(ActiveSheet.Range("M8").Value)
Me.TextBox9.Value = CStr(ActiveSheet.Range("M9").Value)
Me.TextBox10.Value = CStr(ActiveSheet.Range("M10").Value)
Me.TextBox11.Value = CStr(ActiveSheet.Range("M11").Value)
Me.TextBox12.Value = CStr(ActiveSheet.Range("M12").Value)
Me.TextBox13.Value = CStr(ActiveSheet.Range("M13").Value)
Me.TextBox14.Value = CStr(ActiveSheet.Range("M14").Value)
Me.TextBox15.Value = CStr(ActiveSheet.Range("M15").Value)
Me.TextBox16.Value = CStr(ActiveSheet.Range("M16").Value)
Me.TextBox17.Value = CStr(ActiveSheet.Range("M17").Value)
Me.TextBox18.Value = CStr(ActiveSheet.Range("M18").Value)
Me.TextBox19.Value = CStr(ActiveSheet.Range("M19").Value)
Me.TextBox20.Value = CStr(ActiveSheet.Range("M20").Value)
Me.TextBox21.Value = CStr(ActiveSheet.Range("M21").Value)
Me.TextBox22.Value = CStr(ActiveSheet.Range("M22").Value)
End Sub

'Insert Button
Private Sub CommandButton1_Click()
Range("M1") = Me.TextBox1.Text
Range("M2") = Me.TextBox2.Text
Range("M3") = Me.TextBox3.Text
Range("M4") = Me.TextBox4.Text
Range("M5") = Me.TextBox5.Text
Range("M6") = Me.TextBox6.Text
Range("M7") = Me.TextBox7.Text
Range("M8") = Me.TextBox8.Text
Range("M9") = Me.TextBox9.Text
Range("M10") = Me.TextBox10.Text
Range("M11") = Me.TextBox11.Text
Range("M12") = Me.TextBox12.Text
Range("M13") = Me.TextBox13.Text
Range("M14") = Me.TextBox14.Text
Range("M15") = Me.TextBox15.Text
Range("M16") = Me.TextBox16.Text
Range("M17") = Me.TextBox17.Text
Range("M18") = Me.TextBox18.Text
Range("M19") = Me.TextBox19.Text
Range("M20") = Me.TextBox20.Text
Range("M21") = Me.TextBox21.Text
Range("M22") = Me.TextBox22.Text
Range("A25").Value = "Hide"
Unload Me
End Sub

Sub CommandButton2_Click()
'Cancel button
Unload Me
End Sub