Just sort of piling on to the points that have been made, and adding my voice to the chorus . . .
I agree that you are being mistreated, or more precisely, undertreated, probably based on out of date or simply superficial understanding. 500mg of metformin isn't going to do the job. First, it's a low dose, close to the minimum, and second, even the maximum dose (which, depending on which expert you ask, is between 2000 and 2500 per day) is extremely unlikely to get an A1C of 11 back down where it belongs.
Nowadays there are far more effective tools available to deal with chronically high blood sugars. Insulin is just one of them, although it's by far the most powerful weapon in the arsenal. The Joslin Diabetes Center, pretty much the institutional gold standard of diabetes clinics, frequently puts newly diagnosed patients on insulin regardless of their specific type of diagnosis, often just temporarily. The idea is to get blood sugar back down where it belongs now, then use the breathing room thus acquired to map out a long term program and strategy.
But a much more fundamental problem with insulin is the stereotyped attitudes toward it. Although it's beginning to change (glacially), our culture, led by the medical profession, has been deeply indoctrinated with the belief that insulin is a "last resort" and somehow an admission of failure or desperation. What utter nonsense! If you have a problem to solve, don't you want the best solution available?
Think of it this way. If you had a broken leg, would you try just keeping off it for a while, and only have it set and put in a cast as a "last resort" if nothing else was working? It's simply a matter of the right tool for the job. Full stop.
I'm not saying that insulin is the right answer for you. That is something that needs to be decided between you and an endocrinologist. What I am urging you to do is not to foreclose your alternatives before you even start. Keep your options open.
And one last point: an A1c of 11 is way too high and needs to be gotten back down, obviously. But it's not a cause for panic. Mine was a great deal higher when diagnosed 21 years ago, and I'm still here and (so far) complication-free. You have time to solve this. Take a deep breath and proceed. And remember that you have a whole community of people behind you who (a) get it, (b) care, and (c) are always here for you.