You're being psychologically abused by your mother. Her mocking you for being "a fat fuck" when you're very lean now and anorexic in the past is a clear sign. Additionally, I'll hazard a guess you were fat as a child when she was responsible for feeding you and teaching you nutrition. Your unhealthy aversion to food is unsurprising, for the same reason it'd be unsurprising for you to sit in the dark if she screamed at you every time you turned a light on. Best advice? Tell her you will not tolerate any comments from her regarding your weight unless it exceeds a gratuitously high threshhold (e.g. 250lbs). On pain of immediate, permanent ostracism for abusing you to the point you developed anorexia (130lbs). If she escalates in response to you setting that boundary, repeat the process. "You are not allowed to mock, threaten, shout, etc in response to me setting a healthy boundary. If you violate that boundary, there's the door." Hold her to coffee shop standards and tell her as much. If you wouldn't tolerate the remarks or tone from a random barista at a coffee shop, you wont tolerate it from her. Require her to either adhere to those basic standards or yeet the harpy.