hi Code 50,
back injuries are tough, and it can be a long and difficult journey ( so speaks the voice of sad experience)
You must get some treatement and support for your depression, and it must be multi focal.... by that I mean set yourself some forward looking challenges as well as the pharmacological and psychological support you need.
Perhaps you could think about what you would have done if you hadn't chosen nursing and give it a go....a new challenge will occupy your mind, a new skill is no load to carry in life, and if the worst happens and you are unable to resume your career you are off in a new direction.
It doesn't have to be a major goal just a new and different focus, at the risk of being simplistic it sometimes helps to see oneself as a good say flower arranger... rather than a broken down nurse.
I hope you don't think I'm patronizing you but I have been on a journey like yours and I came out the other end sane ... I think!!!
Sorry to other readers for hijacking the purpose of this thread but felt I had to answer.