I couldn't find any special law in TN related to runaways, so there doesn't appear to be any exemption like you want. Therefore, until you reach the age of majority (18), you need to do what your parents tell you.
If your home is unsafe or you are being abused, contact child protection services in your state. But other than that, you have to stay where your parents tell you - like it or not.
Oh, and btw, TN doesn't have a statute for emancipation, either, so that wouldn't be an option. Even if it did, you probably wouldn't qualify since you want to live with your bf rather than being fully self-supporting.
ETA:
TN does allow for a runaway shelter:
Part 5 Tennessee Runaway Act
Note, however, that the shelter must be registered with your state (so your BF's home does not qualify) and they must notify the parents and they can only keep you for 72 hours.
Read the last section of that law - penalties. Your BF could be guilty of a Class C misdemeanor for sheltering you against your parents' wishes.