Noodle ~
The only thing I can add to the previous responses is to reiterate that post-op, regaining balance function is often a long process and never finite. I'm coming up on 4 years post-op with a splendid recovery (no real issues) but my balance, while serviceable, is not 100%, although I have no real problems and nothing to complain about.
You were wise to contact your doctor and he is admirably responsive in ordering a 'fresh' MRI, as a precaution. I seriously doubt that you would experience a re-growth (our biggest concern) in six months but the MRI can assure you of that and give you peace of mind.
Recurring balance issues are definitely irritating and you may have to deal with them awhile longer but exercise and possibly vestibular exercise, as Clarice suggested in her post, might be of help to you as you struggle with balance issues, which are common to post-op AN patients. I hope your equilibrium problems will soon resolve and you can regain the quality of life we all seek.
Jim