Hi k_nyc and welcome to this forum .....
It sounds like you have received good advice from Dr. Selesnick. Your AN is very small at this point and growing only slightly it seems. Some people experience a stopping of growth all together or at least for a period of time. This gives you time to do your research. It is always good to seek another opinion, even though you might go back to your original physicians. There are several highly experienced AN physicians around the country who will do free evaluations if you send them your most recent MRI and information on your history. Dr. Selesnick is right in that the decision to move forward needs to be the patient's decision after getting opinions from experienced AN medical people. It is your body and you need to do this when it is right for you.
As for the tinnitus, unfortunately it often does not improve no matter what you do. There is much research being done on tinnitus, but one of the most current beliefs is tinnitus is the result of the brain wanting to compensate for even minor loss of hearing. There are many factors in individual patients to cause it to increase besides tumor growth. I have tinnitus and I find that mine is much worse when I drink too much caffeine, have too much salt, or when I am stressed. Other people have different triggers.
Best wishes and keep in touch with any other questions or comments.