I'm in the same boat as far as the braces and adjustments go...but I'm not vegan. So, a lot of the foods I eat won't work for you (omelettes, scrambled eggs, certain soft meats such as salmon, etc.). I imagine even yoghurt and cottage cheese are out in your case too, given the restriction against dairy...correct?
I also eat soups, and there would be some soups (vegetable, etc.) that would work for you, plus protein shakes and smoothies. I also find that, after the first couple of days, I can eat a salad, as long as there's nothing too crunchy in it.
All that said, my calorie count goes way down right after my adjustments, since it is quite painful to eat anything for the first few days.