First off, welcome to the forums!
That is certainly NOT a situation to pull your firearm. I think that you'll find that to be a no-brainer answer from most folks here. I would like to strongly suggest that you look into taking some sort of defensive firearms course. A good course should thoroughly cover when use of deadly force is appropriate based on the laws of your state. In addition, do some research yourself. Visit the Tennessee portion of the boards. They can direct you to the actual laws of your state and likely suggest reputable trainers in your area.