Please don't give up. My mother has anorexia, and has been battling with it since she was a teenager. At one time when I was 15 her weight went down to 20-something, and was clinically brain-dead.  Still battles with it today, once or twice a year has to go into hospital so she can be monitored and increase her weight. Very hard for all the family, but there is nothing to be gained from giving up. Keep battling, keep fighting.