My mom predicts I'm a failure, what can I do to help myself?

This is probably the 50th time my mom scolded me over the past year. My mom's standard towards everything is extremely high. That is If I didn't achieve 100% on everything, she scolds me. Due to family situation I have to live with my mom and become a mama's boy. She doesn't have a job but hope me to buy her a house. I graduated from college a year ago and don't have much experience to get a $60k+ job. I have a low skilled job that doesn't pay much. I just don't have a power brain filled with entrepreneurial spirit. Recently I'm taking courses at an university. My mom told me having so many college degrees doesn't differ from idiots and retards on the street, and I better stick with hard labor job even with my Certified Accountant title. One morning I was making coffee, but mistook salt for sugar, my mom saw the chance and began scolding me for making such a mistake. She said "only idiots will put salt into coffee, you have to admit yourself that you brain is severely damaged and no longer function like normal human being. There is no use even you get your new degree..." She went on and on, from one extreme to another, and was hurting my morale.... I marked on the calendar to record the day she scolded me, and predicted the next one will hit me 2 weeks after. It doesn't matter how often she scolds me anymore, I just don't want to feel like a complete failure, anybody have any idea how I get it over with?