my dept supervisor admitted to a fellow employee that she(supervisor) intentionally harrassed me in order to force me to quit.

In New York, when a person is harassed to the point where they reasonably decide that they have to quit, it is known as a "constructive discharge", and is treated as if the employer had terminated the employee without good cause.  HOWEVER, if you were, as most employees are, employed at will, your employer could terminate you at any time and for any reason (other than statutorily prohibited reasons, such as race, gender, religion, in retaliation for certain types of whistleblowing, etc.)  The employer is allowed to fire you without good cause.  Thus, if you were an employee at will, and the decision to get you to quit wasn't motivated by your race, gender, nationality, etc., you have no claim for constructive discharge.