I don't practice in TN and the first advice I can give is for you to talk to an attorney in your area. I can tell you that where I practice in FL the cops will often tell my clients don't worry just get your license and it will be dismissed. Occassionally that may happen but more often than not the prosecutor will continue to charge it as is and "cut you a break" by not putting you in jail. While it is always best to get your license straightened out as soon as possible which can only benefit you, my point is don't necessarily believe what the officer is telling you. That's why you should talk to an attorney in your area.
Yes, if you pay all of your fines and costs it is possible to have the case retired or dismissed. The DA will look to see if you have any prior driver's license charges, and if you don't will usually be able to work something out. Who the presiding judge is for yoru case will also be a factor.