My parents favor my brother and it is getting out of hand?

I am bulimic and my parents ignore the fact that I am. When I told my mom about my issue...the first thing she said was "well can't you just stop throwing up?" Evidently, it is easier said than done for somebody with an eating disorder. I asked to talk to my therapist but she never got around to it. I also suffer from anxiety and ocd. My brother on the other hand get's the better hand. Whenever he needs something my mom will get it for him. all i ask for is a trip to talk to my therapist and my brother gets 3 new video games instead? How can I express my discontent towards my mother without sounding too self serving.