My mom is upset with me..?

I am anorexic and I have depression and an anxiety disorder. I've been going to therapy, seeing doctors, and overall, I'm really resource and time consuming. My dads been out of town for two weeks and I have a 13 and a 3 year old brothers so I'm tryin to help out around the house by cleaning, cooking, and doing other chores. My 13 year old brother watches my 3 year old brother and gets lots of thanks and praise. When I help, I get thanks but I just feel unappreciated and really guilty all the time. I try to relieve my moms stress but I'm not good enough. I tried talking to my mom about how I feel and she said 90% of her time and resources go into me and she's overwhelmed by me and says I'm mentally distorted. She says that the things I do to "help" are just things that should come natural when you're a part of a family and that I should do those things automatically. She says that she never knows what she's gonna get when she talks to me cuz I might be angry or moody and she feels like she never says anything right to me because I'm so sensitive. For the last 2 hours I've been crying so much and I feel so useless and guilty I want to die.. I'm never going to be good enough and helpful because I'm so high maintaince and difficult to my mom. I hate myself and I wish I could be a good person. I try so hard but it's never enough :'( please help me!!! :(