I had 2 TURBTs early this year and completed 7 rounds of Mitomycin C (MMC) chemo treatments earlier this year.
While the whole process sounds scary in the beginning, I found the treatments and the side effects to be very tolerable. No one likes catheters, but overall the process took less than 15 minutes, and then I could go home.
I had to hold my bladder for 2 hours, and then carefully clean/disinfect the bathroom. I did find I had a lack of appetite, but I wouldn't call it nausea, and as the weeks went on I was increasingly less energetic as the day went on ..
My treatments were on Friday and I found myself tired until about Sunday afternoon by the last few treatments.
Other than that, I didn't really experience any bad side effects at all and consider myself lucky. I have had 2 Cystoscopys since, and so far nothing has come back!
I am happy to answer any questions you may have.
Best of Luck-- you will get thru this...