It's easier to put the steps from the begining, so you might have done few of
the steps.
To add new fields to a form that is bound to a table:
1. Add the fields to the table that the form is based on
2. Open the form in design view, open the form properties and view the
Record Source of the form, if only the name of the table is written there you
can continue to the next stage, if it has a select statement you need to add
the new fields to the RecordSource of the form, but this time specify all the
fields, incase you'll want to add new fields again you'll be able to skip
this stage.
Locate the cursor in the RecordSource, you'll see on the right a button with
three dots, press it and you will see the SQL of the form.
Select TableName.* From TableName
3. Add the Text Boxes to the form, open the properties of the text box, one
of them called ControlSource, locate the cursor in it and you'll see that
it's a combo where you can select a field from the table, select the new
fields.
4. Save, Close, Run the form and I hope it will work