Legal Question in Civil Litigation in Georgia

Unless you have a contract where she agreed to pay you, you made a gift and you can't sue to get gifts back.

Lawsuit for what? Since you failed to state whether this was a loan or a gift, and the terms of the loan, I am not sure how you expect an answer. Did you have an agreement that she could not break up with you for a certain amount of time to avoid paying you back? If you simply gave her the money (directly or by paying the bill), without an agreement that it was a loan and she was going to pay it back, it is a gift. Treat it as a lesson -- personal and financial.