In the below example I just created a collection of textboxes
and looped through them adding the x and y coordinates from the textboxes
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
Dim Xtbs() As TextBox = {TextBox1, TextBox3, TextBox5}
Dim Ytbs() As TextBox = {TextBox2, TextBox4, TextBox6}
For i As Integer = 0 To Xtbs.Length - 1
Dim x As Double = Xtbs(i).Text
Dim y As Double = Ytbs(i).Text
Dim pt = New DataPoint(x, y)
Chart1.Series(0).Points.Add(pt)
Next
End Sub