Anyone ever killed and chopped up feeder or pet fish?

I had a baby red eared slider that would not eat for over a week. I tried many different pellets. I tried puting live fish in there but it could not catch them. I tried killing the fish but they were too big for it. I had to chop up the fish and the turtle would then be able to eat it. I then switched to tiny feeder fish and did not need to chop up. I felt bad and uncomfortable... the things we do for our pets. And I could not even the turtle (gave it to a pet store) cause we thought we were moving into my inlaws tiny trailer for a few months!.