Your mom is fat because all she does is sit around and play Destiny. Her sedentary lifestyle, paired with copious amounts of Mountain Dew-flavored Doritos, has made her all but desirable to the opposite sex(as well as the same sex). Her unwillingness to graduate high school hasn't helped much either. She can't hold a job for more than a month, she's lost all contact with your family (aside from you, OP), and she's falling into deep depression. Please, get her some help.