Since you have your form fields in a repeated region, you will need to make sure they are named uniquely. Do that by appending the productID column from the database to each like:
name="“eCart1_1_Quantity<?php echo($row_WADAProd['ID']); ?>"
Then, since you are adding more than one item at a time you would have to remove the "Add to Cart Button" server behavior and instead use "Get Cart Contents from Recordset" which can be used to add more than one row at a time.
When you bind the values in that interface you will refer to the form elements with the appended productID so that you can get the appropriate setting for each. It will automatically ignore any rows whose quantity is not set or is set to zero.