Cooked fish is fine as long as it hasn't been sitting around, same with Sushi and Vege rolls. It's the rice that you need to be careful of the most though - make sure it hasn't been sitting around for ages.

Before being diagnosed with Gestational Diabete's I ate Sushi ALL THE TIME! It was one of my major cravings, especially the California Rolls lol but now the rice puts my blood glucose levels through the roof so I can't eat it anymore
Enjoy it while you're able to And homemade is definately best too