You will want to fill out a new W-4 with your employer to adjust your withholding. You could request to see a copy of your current W-4 that they are using to base your withholding on, and then adjust from there based on the tax calculator results.
Tennessee doesn't currently have an income tax so no need to be concerned with any state withholding if you are living and working in Tennessee.
Hope this helps!
Cindy