People are not property. They cannot be left to other people. Your parents probably named the other couple to serve as your guardian after their deaths. That is not binding on a court. However, the courts tend to follow those statements unless there is a good reason not to. If your guardianship was initiated in Georgia, it should have been transferred to Tarrant County when your parents moved here. If it was not transferred then you would have to go to the court in Georgia to have it terminated. If it was transferred to Tarrant County, you would go to that probate court (there are two) to have it terminated. The Tarrant County Probate Courts have a guardianship office. Call them when you are ready.
DISCLAIMER: This is not specific legal advice and does not establish an attorney/client relationship.