Driving on a revoked license is a crime in Tennessee. Generally, the punishment is a sentence of up to six months and a one year loss of your license. Also, if your license was revoked as punishment for DUI conviction, you face a mandatory 48 hours minimum of jail time.
It is impossible to inform you what will happen in your case. If, you have already been charged with the offense, you should hire a lawyer to reach the best possible outcome. If you have not been charged, you should definitely hire a lawyer to advise you on how best to respond to a police investigation because you may be able to avoid criminal charges at this point.
You will likely get a citation for driving on a revoked license. If you get lucky, you might get an officer who feels sorry for you and simply warn you about driving. If you do get a citation, get an attorney to help you. In some counties the state will want you to serve some days, but an attorney should be able to get the case dismissed once you get your license back. Good luck!
You could be arrested or cited for driving while license suspended, revoked, cancelled and charged with the accident as well. If your car impacted and caused damage to someone's car or property or something belonging to the City or another Company (i.e., guard rail, telephone pole, etc.), you will be liable for the repair of that as well. Unfortunately, your driving out of necessity, will not provide you with a defense in this situation. Good Luck!
I am not licensed to practice in TN, but driving on a revoked license is surely a crime in TN. The fact that you fiancé had consumed alcohol does not excuse your driving. You probably could have just not driven, called a taxi, found a hotel/motel and waited overnight for her impairment to resolve or called a friend to drive. You probably will be charged with a crime. Good luck.