It sounds like your dizziness is really taking a toll on you. You must be very frustrated at this point... it can sure be scary, especially at first. As you start doing research, you will likely learn that there are many different stories about these AN tumors and each person's experience is different. For starters, it's good that your ENT was diligent enough to check you for an AN. Based on what you've said it sounds like your balance is your main concern at this point, and of all the symptoms you are having it is the balance issues that are effecting your life the most. With that in mind, I would ask your ENT or primary care provider to order vestibular testing for you (often referred to as a caloric test or balance test). The results of this testing can provide information regarding the health of your balance (vestibular) nerves, and is helpful in predicting outcomes of different treatments.
As you move forward with your planning and research, please keep in mind that the vast majority of AN patients have good outcomes no matter which course of treatment is taken (surgery, watchful waiting, radiation). Use this ANA website as a starting point for your research, get several opinions from well qualified doctors, and ASK QUESTIONS. Somewhere on the ANA website is a list of questions you should ask your doctors, it is a good list and it also helps you to start prioritizing what is most important to you moving forward.
Keep us all up to date, ask us a lot of questions and stay optimistic.