New Mom With Breast Feeding Anxiey

Hi ladies. My sweet baby is one week old today and I have had her on a 50/50 (approximately) breast milk and formula diet. I was very strict with my diet in pregnancy and, for some reason, completely forgot there are still rules involving my diet and breastfeeding as well. I have been having tuna salad cravings + I had sushi the other night. In this one week, I had 3 tuna salad sandwiches and a serving of sushi! Today, the whole thing hit me and I freaked out. I asked a nurse if I should lay off the breast milk for a week going forward and she said no, and that I'm not going to hurt the baby with just one week of too much fish, but I'm just so nervous!! Can someone ease my mind? I just want wants best for my little sweet girl.