How much weight can I lose?

Don't worry so much about your weight. The diet you're on is healthy and will make you feel better! I would recommend throwing in a bit of tofu (a tofu scramble is great for breakfast, it's as good as eggs) or tempeh (delicious on a sandwich). If you keep up a balanced diet of fruits, vegetables, and proteins, plus vegetarian vitamins to make sure you've got everything you need, you definitely will lose some weight. But remember that working out more will make you gain muscle which weighs more! Don't look at the scale, look at yourself and think of how you feel. That's more important.