I'm sorry.

It's tough losing a patient, especially one who struggles so much with a mental health issue that no one else can see on a scan or a test---only by their behaviors. I've lost a few and I always tell myself over and over that they are
finally at peace with this horrible internal mystery that has been tormenting them for so long..... this illness that lead some of them to have the crummy home-lives that they had.
Good for you for giving her all the time that you gave her. You will be (already are) a great nurse.