Threatening Roommates

My question involves landlord-tenant law in the State of: Tennessee

Ok, I have signed a one year lease with my roommate. Things have just went sour and I'm not sure what to do. First off, she has her boyfriend living there (he has since we first moved in), and he is not on the lease. He has no job and is paying no bills. How can I prove he's living there? Considering we are not allowed to Sublet. We have placed the gas bill in her name and the power in mine in attempts to split the utility costs, but now she's threatening to take me to court for not paying a portion of the gas bill. I have never paid on the bill, nor have I signed anything stating that I would. Can she press charges on me? Also, the property management informed me that the only way to get off the lease is if both parties move out or if a new lease is signed. I recently realized that the apartment number on our lease is incorrect. Would that justify a new lease to fix the problem, or would it be looked over as a typographical error? I have received very hateful text messages from my roommate. My apartment keys coincidentally went missing. I haven't physically resided there in almost 2 months because I fear things will get violent, considering her boyfriend has an assault charge on him already. I just want out and if I need to force an eviction I will. Can anyone give me advice?

You can report your roommate's unauthorized long-term guest to your landlord, and let him worry about what to do next.

If she sues you for half of the gas bill, go right ahead and countersue for half of the electric bill.

I have no idea what you're talking about in relation to her "press[ing] charges on me". What crime is she suggesting that you committed?

Having the wrong apartment number on your lease is an irrelevant clerical error. You accepted and moved into the apartment you're in.

If you choose to live elsewhere, that does not get you out of your lease.

You are free to propose to your ex-roommate that she enter into a new lease with the landlord and release you from further obligation, assuming you're still contributing to rent and/or utilities.