have you ever told your abuser to fuck off?

I have some sickness where they are testing for internal bleeding, infection and cancer. I have been nauseous for a month now so they are trying to figure out why. my abusive mother asks me a favor and says to review my brothers resume for a deadline at 12 midnight. she was doing it at first, but wanted me to help. it's the early afternoon. I tell her I am sick and literally just came from the hospital but I say I'll take a quick look. then after 15 min I tell her I can't because I am nauseous and maybe need to eat. I eat and tell her I can't review because I am sick. she says can't you just review this, it's due today. then I tell her I really can't, I am sick. she demands "why don't you just go over it? you always help neighbors and at work but when it comes to your own family, nothing." I tell her "you asked me a favor. I am sick and nauseous don't push me. do you not care about me? fuck off." and then she goes on to attack my character sayingthat I am a horrible person. she always does this and this isnt the first time. the last time I was really sick like this and throwing up was a few months ago, she screamed at me because she was upset that she bought a plane ticket for me on a trip that I told her I don't want to go on months in advance. she still bought the tickets without my consent and then yelled at me when I told her I can't go on the trip. as a child, she would also scream at me when I was sick and force me to go to school when I had the flu because there was a test that day. when I first started work, she also would yell at me and force me to go to work a day after my aunt died and my coworkwers were telling me to take bereavement leave because I was crying at the office. anywho, have you ever told your abuser to fuck off?