I believe you have to start with the language you use. Calling a disease your "friend" and personalizing it allows you to hold on. You miss certain aspects of the harmful behavior. You miss the feeling of control. You can admit that. Find other, healthy ways to meet your needs. A disease isn't someone you visit with over coffee. It's a sickness.

Don't let go of knowing better, it's what makes you whole...it's your strength.
If you forget the dangers of Ana, you're allowing that backstabbing bitch of a friend to get back in your good graces, just so she can steal all your boyfriends and backstab you once again. (okay not in that exact way, but you get it haha). She's the ex-best friend you are muuuuch better off without, the asshole ex boyfriend that was impossible to move on from, but once you do you realize how greater life can be.
Don't give in. Relax, and stay strong :)

I know it is hard. I really want to write something positive on here but it is too hard. I can't imagine life without the one shitty friend I always rely on. I try to think though, they are there for you when you feel at your worse, but never there to help celebrate the good times. This friend only likes you when your needy and down. But it is hard to let go of the shittest of friends, even real ones! hehe!

you dont need anna, anna needs you. let go and get your life back