I'm very sorry to hear of your situation.
Under the circumstances, while you may be titled as a manager, as management of employees is not your primary function, and because you do not have an advanced degree, then it is inappropriate, and unlawful, for your employer to continue to classify you as a Salaried Exempt Employee---regardless of what your salary may be.
Under the circumstances, since the time that you ceased supervising at least 2 other company employees, you have been entitled to overtime pay. If the employer is unwilling to pay you the back pay you are owed and persists in their decision to mis-classify you as exempt, then you will want to consider legal action.
You may actually sue the employer and recover your wages. Additionally, under federal laws (FLSA), you are also entitled to what is called Liquidated damages. Liquidated damages is equal to the amount of back wages that they owe you and must be paid in addition to the wages themselves---so you essentially get double overtime wages in the claim based on their willful failure to pay you. http://labor-employment-law.lawyers.com/wage-and-hour-law/Liquidated-Damages-and-FLSA-Claims.html
Here is an excellent article which deals with pursuing an FLSA claim---which you may do in either state court or federal court. Do take the time to review it:
If you have not yet seen this particular web page, it provides a good primer of what makes a person eligible to be designated as salary exempt under federal law:
You may reply back to me using the Continue the Conversation or Reply to Expert link if you have additional questions; and if you do, I ask that you please keep in mind that I do not know what you may already know or with what you need help, unless you tell me.
Kindly take a moment to rate my service to you highly, based on the understanding of the law I provided. Please understand that I have no control over the how the law impacts your particular situation, and I trust you agree that it would be unfair for me to be punished by a (negative rating) ----the first 2 stars/faces----for having been honest with you about the law.
I wish you the best in 2012,