My Manager Has Been Rude, Threatened My Job Multiple Times All After Finding Out My Boyfriend Was White...

Location: Tulsa Oklahoma.

My Sales Manager was seemingly nice to me when I first hit the sales floor. We got along fine for two weeks. Then I placed a picture of my boyfriend and our baby boy in my cubicle. Let me first start by saying I am Black and my boyfriend is Caucasian. My Manager saw this picture and said "cute baby" then she increasingly became hostile, making comments about my job performance (the amount of sales I was making) and kept making slick comments about how I could get fired if I didn't make at least 3 sales a week. I have always made at least 4 sales per week. So there was no real reason for her hostility in my mind.

She sat me down for a weekly coaching and asked why I looked bummed out that morning. I told her I got into an argument with my boyfriend before work and things were just tense at home at the moment. She asks his name, I tell her. She then asks if he is White, of which she already knew that he was. I replied anyway and said "Yes." She then smugly whispers to me "You can't let the Slave Masters treat you any kind of way." Looked at me like I was disgusting or beneath her. I sat there with my jaw dropped and finally rolled my eyes at her and said "wow, okay." And I went back to my desk. Her hostility continued for several weeks and she tried to get me put on probation for lack of sales at work. Again I always met my sales quotas. Finally I had had enough and I quit. It was a hostile work environment at that point because of her, she was talking about me behind my back to the other managers and my coworkers for no reason at all. Reprimandeding me on the sales floor in front of everyone. People started asking me what I did to her to make her so rude to me. I don't want her doing the same thing to someone else. I was prescribed antidepressants by my doctor while working there because I dreaded dealing with her when I went to work and it was affecting me mentally. What legal action can I take?