The problem is not with your drop down list--it's with your table and field design.
When You option drag a field, you are just making a second copy of the same field. Thus, what you enter in one field will appear in all the fields you have created this way as they are really the same field.
For best results, you need a portal to a related table such that each row in the portal is a separate related record.
Here's a simple demo file created by Comment that illustrates this design approach: http://fmforums.com/forum/showpost.php?post/309136/
i figured that was the issue. i am having trouble with how to go about creating separate related records inside the portal.
First, look up Portals in FileMaker help so you can get a basic introduction to this layout object.
You'll need to define a table in Manage | Database | Table and then click the relationships tab and related the two tables. Open the demo file and use Manage | Database to examine the tables, fields and relationships defined in it to get a basic idea of how this can be done.