Hi, Mindy. I'd say definitely wait. As Jim points out, 12 weeks won't make any really difference either in your age (and therefore "ease" of surgical experience) or in the size of your tumor. I understand that tumors sometimes "swell" after treatment and before they begin to shrink, in which case, your tumor "growth" could be a good thing. And my surgeon tells me that you have to see a continued increase in tumor size to say there's actually any growth because even a very small difference in the position of your head during an MRI can affect the position of the tumor, making it appear larger or smaller.
I've had ret sig surgery, and while my eventual outcome is excellent (and I'm a lot older than you are--54), I can assure you it is not something to undertake if you don't have to. My episode with facial weakness, if nothing else, convinced me of that. I'm lucky that my problem was overcome very quickly, but for some people, facial weakness or even paralysis is permanent. And there's the likelihood that you'll lose the hearing in that ear. Being SSD is not the worst thing in the world, but it is annoying and inconvenient, and it can affect your lifestyle significantly.
I can understand the impulse to get that tumor out at all costs, but since you chose and underwent CK, give it time to do its job before you try something else. And, while I'm the first to question (and often to disagree with) a doctor, you have a good guy taking care of you, so unless you have good reason not to, at least listen to his opinion on this.