As usual, OT really has hit on some issues here. No doubt the idea of boundaries is something you really need to give some thought too because without them, you're only becoming further a part of this drama instead of rising above it.
Obviously you'll never be able to save him or fix him, its something he needs to be able to do for himself. As sad as it may be, this really can never happen until you establish some clear lines and stop enabling him to continue on this merry go round.
I'm not being critical, just trying to give you an insight as its something I know I struggled with in my own relationship. Its very hard dealing with someone who is hell bent on destroying their own life at the cost of everything. There is no way that you can control their actions, behaviors, thoughts, etc...and sometimes that's hard to accept.
On my homefront, things have improved to a degree. OM hasn't been a factor for quite some time and we have worked to try and improve our relationship with each other and learn to communicate in healthy ways....however, dealing wtih an anoretic and emotions and/or feelings is like trying to teach a bear to ride a bike. Completely unnatural. So in that sense, any chance of a truly, healthy relationship is put on hold and becomes secondary to recovery.
On that front, I think she has come a long way from where she was even a year ago. Back in October, she had a stint in a eating disorder clinic for about a week and, given her lack of committment to recovery and everything else, she just slipped back into old habits and behaviors (very predictable). Since then, I think she's gathered more courage and insight and is now planning another inpatient program in Baltimore for the week after Easter. The plan is a three to four week inpatient program, followed by intensvie outpatient sessions (generally 12 hour days with group and individual therapy, nutrition counseling, etc). I am hopeful that she will follow through with her recovery plan, but its hard to be optimistic once you learn the hold that his thing can have on people....
Soooo, in the meantime, I recognize that my role in this relationship, at the moment, is more of providing support, empathy, and love. I'm not going to get much in return because on the scale of importance, her eating disorder will be the number one priority, with me in a distant second. That's not to say that she doesn't try, because she has really been very happy with the way things have turned for the better in our relationship, and she shows it in any way she can. But its very hard to be truly "happy" when you can't even be happy with yourself.
"Achieve success, but without vanity; Achieve success, but without aggression; Achieve success, but without gain; Achieve success, but without force." Lao Tzu
