Balance issues sort of "go with the territory" when you have an AN (vestibular schwannoma) because the tumor begins with the multiplying of the schwan cells (outer layer) of the vestibular nerve (the balance nerve). The good news is that we have two vestibular nerves and the brain is a wonderful organ to transfer the signals to the good nerve on the side opposite the AN. The problem comes when at first the brain is receiving poor quality signals from the AN side and good on the other ..... and it does not know what to do with these mixed signals ..... hence, the dizziness/vertigo/wonkyheadedness. So, it is actually a good thing when the poor quality signals stop (through tumor growth or treatment by removal or zapping) ..... then the brain adjusts rather quickly for most people.
To answer your question, vestibular therapy has been shown to speed up the retraining process. My suggestion would be to see if you can find a trained vestibular therapist in your area and have a consultation pre-treatment. Much depends upon where your tumor is located, its size, and what quality of signals you are receiving from the AN side. There are several tests to determine how much function you have. I had several computerized dynamic posturography tests done during the evaluation and course of my vestibular treatment. See http://vestibular.org/vestibular-disorders/diagnostic-tests/posturography-cdp.php
The balance issue should be relatively short-term so unless you are an ironworker, climbing high beams
you should be OK.
Obviously, you should also check with your physician when you have your appointment in December.
Best wishes and let us know how you are doing.