I have CLL. I know it's a shock to be told you have leukemia, that it's not curable, and they don't intend to do anything about it right away!
The watch and wait phase can indeed last a long time. If your immune system is currently strong and you have no other indicators of aggressive disease, then go on with your life. I was in W&W for almost 6 years during which I worked as a substitute teacher in elementary schools. My immune system worked fine and it seemed like I got sick less often than most people. Currently, I am in 6 months of treatment, necessitated by an enlarged spleen. Prior to treatment, my immune system was still working fine, but treatment has really battered it. I am not currently teaching, but others CLLers continue to work during treatment. Keep in mind that people with CLL often have long remissions (5+ years) between rounds of treatment. Starting treatment is not the end of your life.
I suggest you check into some excellent online resources:
CLLSLL : CLL and SLL
All of these resources have excellent information both personal and clinical. As a nursing student, you will probably appreciate the high level of interest among the discussion participants in being active advocates in our own care.
Best wishes for a long wait!