Physically Drained

I'm tired so very tired. I haven't really done a thing. I have sat in my chair, Minding my own business. Doing my own thing. My work has gotten done. On time and correctly, I might add. But still that isn't enough for him. He wants more and more work from me. I am doing my best. Why is he picking on me? He has called me out And embarrassed me. I ain't got no help in here.