Why are you not sure that you are married legally? Tennessee does not recognize common law marriages but do recognize common law marriages if they were created in another state that allows them. The states that recognize common law marriages are: Alabama, Colorado, Kansas, Rhode Island, South Carolina, Iowa, Montana, Utah, Texas and the District of Columbia.
You need a lawyer to help you determine whether you are married and, then, if married, how to get out of it or do the separation and to evaluate for what, if anything, you are responsible. There is a lot more information needed in order to provide you with definite answers and a strategy.
These comments do not constitute legal advice. They are general comments on the circumstances presented, and may not be applicable to your situation. For legal advice on which you may rely consult your own lawyer.