Hi Mary, and welcome to our little group!
I agree with Jan. If your AN is now having a major impact on your life, then it is time to act. I would consider both options, surgery and radiation, but make sure you express your concerns over your current vertigo episodes. It is my understanding that radiation usually will not affect the vestibular nerver, which means your vertigo could continue. I'm not a doctor, and I could be wrong, so check with someone who doesn't just play one on TV
Having the vestibular nerve killed is an option, but in many cases, that will take out the hearing nerve as well. I also remember a case where someone had that done, but it was not successful (can't remember who it was now). With surgery or radiation, they have a 50 to 70 percent chance of saving useful hearing (depending on the treatment option and the approach). I am single side deaf (SSD) now, but am adjusting to it. My surgery was on March 5th, and I'm returning to work today!
I guess the other option would be to wait a bit longer. I had vertigo, but only for a few days, and then it passed. I never went to the doctor for that symptom. It was hearing loss and tinnitus that devloped later that got me. Your vertigo "may" pass with time as the vestibular nerve becomes more involved with the tumor, but there is no way to be sure of that.
Ernie