I Have Been Obese Throughout My Childhood

I have been very fat my entire life. I was over 200 pounds when I was 9 years old, and 300 by the time I was 12. I hit 400 at 14 and pretty much lost hope at that point. I was always the fattest kid in class, but I could always look at fatter people and think at least I'm not that fat. Now I'm 18 and am over 700 pounds. It's horrible, I feel so self-conscious, people are always staring and making rude comments, and I don't really have any friends.