[Smiling for the World]

A couple weeks ago two of my friends found out that I cut/burn on my hip. They saw while I was changing for gym but I didn't really care because they are two of my closest friends. Later I found out that both of them also cut, which I kind of suspected. We all agreed to not cut anymore. I tried soo hard not to do it again but I broke down the other day, and did it. Anyway, my friend found out about it and started crying pretty bad and she just broke down. I feel terrible for what i put my friends through. Although they both SIed so they understand what I am going through, I seem to be the one that is having the hardest time trying to stop and I do it pretty bad sometimes so they worry a lot. I hate myself for doing this to them. Both of them we're able to stop, But i am so weak and I just couldn't resist.
How can I stop??
How can I get my friends to stop worrying??
How can I prevent hurting them again??