Any Dr that orders an MRI and waits 3 weeks to follow up with you needs to be fired. The other Dr, the one who didn't think you needed the MRI needs to be fired.
Now to the other stuff. I don't know if you have an AN or not. Neither to the Drs you have now. It may even be unknowable at this point even for the most experienced Drs out there.
My situation is similar to yours in some ways. The ENT's locally, three of them, rubbed me the wrong way. They were making educated guesses and ordered an MRI. The MRI shows, without a doubt in my case, a 1cm mass. BUT, my symptoms are not consistent with my MRI. A 1cm growth should not be causing the symptoms I am getting. I'm asking these guys about this and they are dismissing my questions and saying "surgery". Now, I'm supposed to let these guys cut me all the way to my brain stem and they don't even know what I stand to gain from a procedure like that at this point.
So, off to Duke I go to see a neurosurgeon who specializes in skull base tumors. He spends a couple of hours with me and concludes that while I DO have a tumor, he doesn't think it is causing my symptoms! Keep in mind, I didn't suggest this to him, he concluded that on his own. His next step was to refer me to one of his Duke colleagues, an ENT who specializes in VESTIBULAR DISORDERS. He also does surgery, and radiation of skull base tumors. Next month I am spending the day there getting an ENG and other tests to see if we can identify the source of my symptoms and hopefully mitigate them.
So I am going at this two ways. Investigate fully my symptoms for cause and treatment. Secondly, monitor my tumor to see if, over time, I need to take action to arrest or remove it.
Right now you don't what, if anything, is on your MRI. You need to get it to the right radiologist or neurologist to see if they can figure it out. I certainly wouldn't get my head cut open until I know WHY it needs to be done. It may be that the only answer as to what is or is not on the MRI is to wait 6 mos for another MRI, and then another and another until you are 800 years old.
As for your symptoms, there are many types of vestibular disorders, including AN. Find the right geniuses that hopefully can figure out what is going on with your symptoms and disfunction.
Some reading:
http://vestibular.org/understanding-vestibular-disorder/types-vestibular-disorders