Kaisc,
I'm so sorry to hear that she wants to end it. But, she might be feeling that she needs to get herself together and healthy before she feels she can love anyone else. You might want to have a serious dicussion, as I'm sure you already have, about what she's really feeling. Dont take "I dont know" for answers. Her depression is probably really confusing her emotions right now. Try to be patient. If she wants space, try to give it to her, but make sure she knows you care about her, and that you want her to get better, to continue her therapy and whatever medications her doctor's decide to try. I'm sure her feelings for you are real, dont doubt them and try not to doubt the happiness you do give her. I'm not her and I dont know exactly what she's feeling, but I"m pretty positive that she is not pushing you away because of you, but because her depression is warping her emotions.

Let me know how things turn out for you; best wishes!
Ro