Hi Sarah,
sorry to hear that, but i am in the same situation, i was diagnosed with same problem Dec 2015 i am 27 years old. i had the turbt done in Jan 2016 and had my first 2-3 month cystoscopy yesterday. There is no re-occurance found luckily but the normal process is they have a go a regular 3 month cystoscopy for 1-2 years and then annual cystoscopy.
i was worried aswell about same things my future and marriage and about my parents too. I havent told anyone yet, except close freinds.
My history is the same i dont smoke or drink, i do exercise and play sports regularly and take part in marathons, i couldnt believe how this could happen. But i believe there is no exact reason of why this happen but thinking more about it wont change the reality.
i would recommend try to stay positive and healthy and definitely more vegis. Follow the doctor instructions and i dont think its a life thereat at all.
hope this helps
thanks
Sam