Hi, MG:
You are wise to get treated, now that your tumor is touching your brain stem. CK is a fantastic choice for treatment.
Contrary to what you were told, it is entirely possible that you will eventually -- emphasis on the word eventually -- feel better after getting CK, although it may take a year or longer until you do. If your tumor shrinks as a result of the radiation treatments , it can possibly take pressure off the affected cranial nerves and brain stem and reduce your symptoms. (If my memory serves me correctly, Dr. Chang of Stanford told me that about 25% of his CK patients see "gratifying shrinkage" over the course of several years after treatment.)
This fortunately happened to me. Since getting CK in 2008, my balance has improved 90% and my tinnitus is about 90% lower in subjective volume on the vast majority of days.
For sure, I had atypically fantastic results. But it proves that quality of life can improve after CK treatments. You may feel worse for awhile -- a dying AN can exacerbate symptoms and make you feel miserable for awhile -- but eventually you may find that you're feeling significantly better than before you were treated. The best advice I can give is for you to be as healthy in your habits and lifestyle as you possibly can be -- it makes a big difference. As Dr. Chang once explained to me, the damaged vestibular nerve is your Achilles Heel. It is the first thing to act up when your general health goes downhill. So, by being vigorously healthy, you keep that weak nerve functioning the best it can.
Specifically: do aerobic exercise (besides the cardiovascular benefits, this also improves your balance), stay hydrated, get plenty of sleep and avoid refined sugar like the plague. (Sugar feeds brain tumors and is poison for the entire body.)
You will feel better before long!
Best wishes,
TW