Watashi no Doku wrote...
Sounds fairly similar to my situation. I broke up with my ex because she was in a funk in her life and constantly depressed. I stuck with her and consoled her to the best of my ability for a few months, but things just weren't getting any better. While you might feel bad for not being able to help her, you have needs, too. Perhaps spending some time away from each other will give her the insight she needs to get better. I would advise you to remove yourself from her life completely if possible, at least for the time being. Otherwise neither of you will be able to truly move on.
As for a good way to bounce back, I honestly don't know. I'm still working on that. School has kept me focused on the present, and helped me to make new friends. Try giving yourself a few short-term and long-term goals. It'll keep you focused on moving forward.
Sadly, I don't have anything to distract me like that. School and work are both out of the question due to a recent surgery, so I'm basically stuck at home hoping for January to come. The whole "setting goals" thing may work, however, I can't think of anything off the top of my head.