Take a lunch box with you every day.
I'm in South Africa, and am a rep, so have the same kind of issues with available fast food.
I either live on Toasted Cheese and tomato sandwiches, or I take food in a cooler box to work.
What we tend to do now is make a huge supper, and then take a portion for lunch the next day, along with salad, fruit and yoghurt.
Even if you find a veg option at a fast food joint, its not that good for you on a regular basis.