Vi,
Diet is considered a factor for preventing cancer in the first place. While it certainly doesn't hurt and is generally good for you to have a better diet it does not cure cancer.
Hard to ever recommend against diet and exercise.
I suggest that you not "wait and see". My recommendation is that you call ask your urologist for a referral to UCH since it is so close to you. Have them do the TURB (or re-TURB) within 6 weeks of your last one.
Without having a full pathology report that indicates your doctor got good clear margines around the tumor (especially since it was done in his office), you really want to be sure he got it all by having this done.
The UCH is a great bladder cancer center and is close to you. It doesn't mean you don't like your local urogist. By all means, he can probably even do what ever treatment (if any) is recommended by the urologists at the cancer center.
You MAY NOT have cancer. He MAY have gotten it all. Yours was low grade and that is a VERY, VERY, VERY good thing!
You WILL feel better if you go to the cancer center and CONFIRM that the cancer is truly all gone.
I am hoping for the best possible outcome for you!
Mike