If you look on the third page of posts, I posted a lot of tips from our recent trip - they may be helpful. Top 3: get a pocket wifi, buy stuff for in-room picnic "breakfast" for when you are awake at 3am, use 7-11 cash machines with US ATM card.

Absolutely no issues with finding food - plenty of non-fish options are available, but also plenty of non-Japanese restaurants in Tokyo (we had good Thai, Indian and Italian).

Have a great trip!