Domestic Violence: How to Fix the Court's Mistake

My question is regarding the state of Tennessee. In 2005 I was charged with domestic violence. There was no physical contact, merely a lovers argument gone bad that led my girlfriend at the time to claim to law enforcement that she was "in fear" which in Tennessee constitutes domestic violence. I turned myself in, was booked and released with a court date. I appeared at court at which time the acting DA spoke with me and since I had no prior charges we agreed that it would be continued to be dismissed in 6 months with no further contact with the victim. I went before the judge, he stated that it would be dismissed in 6 months with no further contact, I said thank you and went on my way. I do remember the judge telling me in the future to be cautious as I did not want a domestic charge on my record. I never thought any more about the situation. Fast forward 10 years to 2015, I apply for a position with the local police department. I am accepted for hire when I find out that the TBI kicked back that I had a domestic violence conviction on my record. Very confused I contacted the TBI and sure enough, a guilty plea for domestic violence is on my record. I then contact the court in which the charge was heard and request a copy of the disposition. The only record of the charge that exists anywhere in TN is the original arrest warrant, and on the back handwritten it reads, "plea of guilty, no court cost assessed." Bear in mind I paid no fine, no court cost and received no probation, jail time etc. NOTHING. So the record basically shows that I was convicted of a serious crime but wasn't punished lol. I did further contact the DA's office and they have no record of the charge and they were unsure who the DA was at the time. I never signed anything in court either and my signature isn't on any records. I did speak with a Judge briefly who told me that I would definitely remember a Guilty plea as they would have advised me that I wouldnt be able to own or possess a firearm which makes since as I am a very active hunter. I would have definitely remembered that!!! He also said there is no way a judge would simply accept a guilty plea and let me walk without as little as a fine and court cost. My question is, do I just bite the bullet and live with this or is there an outlet for fighting it? I know it's been over 10 years but like I said before I never had any reason to believe that the conviction existed. What are some options??? Also I have never been convicted of a crime since or before. Thank you in advance.

Domestic Violence: How to Fix the Court's Mistake