I also work in a hospital and struggle with balance issues. I, too, wonder how long I will be able to continue working. My acoustic neuroma was diagnosed in November, one month after yours. However, it is small, and my neurosurgeon is recommending a watch an observation approach. So, I have not had Cyber Knife (or any treatment yet). And yet, I still struggle with my equilibrium which is not the best thing in a clinical setting. There have been a couple of times when I have had to reach out and touch another hospital employee to keep from falling.
What my neurosurgeon recommended to me was to have vestibular therapy (which is a little different from regular balance therapy offered by most physical therapists). I just had my first vestibular therapy session last Friday so I cannot give you a report yet on any success. While I was being tested, I fell four times (fortunately, I was in a harness with safety ropes and did not hurt myself). My vestibular therapist said that she believed she could help me to gain at least 90% of my balance back (for my age group) in a month's time.
So, if that is true, rather than to stop working, I would recommend that you explore a vestibular therapist in your area. At least that is what I am doing, and I am hopeful it will restore most of my balance back.