You should take a look at this for foods that you can eat and avoid as a vegan.
You're going to have to avoid a lot of grains, but you'll be eating a lot of greens! Surprisingly after you get adjusted to it, you will not feel as hungry. It will take some time, but you will feel far better in the long run.
You should be OK with flat bread, I.e, bread containing just wheat flour, salt and water. AVOID breads with yeast & sugar.
You can always take probiotics as well as water or coconut kefir.