I used to be a vegetarian and I ate tofu.. there is many ways to cook it, if you don't like it though try this stuff called tempeh, you can cook a lot of stuff with it, and it's really good for you and good tasting too. Also get a vegetarian cook book there is lots of other things to eat besides fruits and nuts and veggies... educate yourself and explore different things.
The gas is normal for now
It will go away...