You know what, I disagree with leaving. She is trying but also has her own pace to consider. There is nothing wrong with that. Putting her foot down might give her some comfort for a bit and that is okay as long as she knows that it has to move forward eventually. That you are not done with the boundary jiust becasue she has decidsed that its done.
I think you need to stop feeling like you are asking to much and stand up for what you need in this relationship with Sam and for your life then go do it with as much respect to her as you can . I also think that she would do well to read this thread and see that people think you should leave. Sometimes that can be a great motivater. Radical honesty; what do you have to loose that you aren't already considering ending anyway. You never know, it might just be the jolt you need to get going on what works better for you and for her. After all, she might do better or decide that working on this just isn't going to work for her.
Anyone want to be friends on Facebook?
Send me your name via PM