If you want to tell your friend about SI so that you can have the option of calling on her for support, I think the important thing is to be prepared to help her learn how she can help. Not everybody is able to deal with stuff like this, so that's something you want to consider carefully, and maybe discuss telling her with your T before you go ahead with it.

That said, one of the best ways you can help her help you is to be prepared to answer her questions, which means you need to find some answers and have a bit of understanding of what it is and why you do it. Here's a good place to start looking: Sweet Crusader's Cocoon . It's by one of our members here, and she has a page for loved ones, as well as links and a book list and other resources.

Best wishes to you, and I sincerely hope that you are able to stop hurting yourself and heal all the way through. It sounds like the support is there for you to be able to beat this. You're always welcome to come here for support too.