The reason you are getting help is because you took that step to receive it. Many people who self-injure do it and nobody has a clue about it, so how can they be helped? I think it's fantastic that you have a large support system to help you overcome your issues, both self-injury and eating disorder.

And also, you are not retarded. You are a wonderful, strong person who deserves to live a happy and healthy life. And I hope that your support system (which you DO deserve, by the way ) will help you through your journey to recovery.