Your boss is setting himself up for a lawsuit. (Score 1)

Your boss is slandering you. I would suggest looking into getting a lawyer. You might want to politely remind him that slavery ended over a hundred years ago ( in this country) and that he does not own you. I am a old fashioned but it seems he has dishonored you and has probably been underpaying you for a long time now. We have a saying in Texas "Money talks and BS walks" and I am sure your state has a similar proverb.