I'll just stop you there.
Yeah it's definitely not easy. I admit the one thing I could absolutely not give up was sushi. Granted, I can count on one hand the number of pieces I've had in the last three years, but I could never permanently say "no" to it.
The other thing is pizza. While I do usually opt for a cheeseless, I'm usually left with the feeling that it misses the point. Sometimes I have to splurge and soy cheese is just too expensive. So what I do is take a small bag of shredded mozzarella and mix it with a bag of soy mozz. I can usually get two pizzas out of that (if I go light). But if I know others will be sharing I just bite the bullet and skip the soy stuff. That way I can get fresh mozz which is so much better, anyways.
Incidentally, people always initially scoff at the idea of a vegetarian pizza, but after they try it decide they like it better because there's so much less grease.