How do I tell my friends about my bulimia?

Hi, I'm fourteen years old, a little over 5 feet tall, and I currently weigh 84 pounds. I'm a bulimic, but I only recently exposed it to my counselor, who then told my parents about 2 months ago. I've struggled with this eating disorder for some time, and I still haven't told any of my friends. They're starting to worry about me, I can tell... but I'm not sure how to explain to them that I have bulimia. In a way I don't want to tell them, but at the same time, I wish they knew so they could help me sometimes. I know... that sounds selfish, so sorry. I'm scared of their reaction. I don't know what to do. Can anyone give me some advice?