Do i have a case against my employer?

Here’s the situation. I’ve been at my job for 4 1/2 years. In the last 2 years I have been treated very differently from other employees. I got 2 raises in 4 1/2 years and employees who were hired after me got paid more than I did. I was the hardest worker they had and the other didn’t work nearly as hard as me. They singled me out they talked down to me called me stupid and they actually are the reason I’m on antidepressants. About 5 days ago I was sick and I text my boss about 2 hours prior to my shift stating that I needed to take the day off. I didn’t go to urgent care until later in the evening when it started getting bad. I asked the urgent care for a doctors note and they gave me one. I was then told I needed to come to the owners home for a meeting with him and my manager who is also his girlfriend. She hasn’t liked me from day one. I went to the owners home and I have them my doctors note and they said they didn’t believe me and that I needed to go get proof of why I was there and if I don’t they won’t believe it’s true and basically I’ll be fired. They were putting serious pressure on me and my fear of retaliation and losing my job I got a fake note even though the first one was completely legit. They were already going to fire me before I even gave them the note. The owner then drove to the urgent care and they gave him my medical information. Is it legal for him to pressure me and retaliate if I don’t give him private medical forms? He also didn’t have me sign a termination letter. Then after he had fired me he didn’t give me my check and he also went and called a hospital to get more information about a precious doctors note. After I was terminated. Also the day before another employee called out 2 hours before their shift and he didn’t get in any trouble. I was treated so badly there I never took 10 minute breaks I work 60 hours a week 7 days a week and got blamed for things that happened when I wasn’t even there. I became severely depressed put on medication I could barely get out of bed. I was late often by 10-20 minutes but the written paper they had me sign had nothing saying that it was a write up or any kid of disciplinary action. Do I have any kind of case here I need help.