I have a field script that contains a field that is also from scripting. Why isn't my script working?

You cannot use a field that contains a field script in another field that contains field scripting.  You would need to combine both field scripts into a single field.
For example: Field A contains field script and Field B also have scripting in it then you cannot call Field A and make it a part of Field B as this will not work,you would probably need to create a common field Script and then call both Field A & Field B script by combining or merging them.