They were purring as I opened the cans and fed them.
What was on your mind when you fed them?
I feel guilty and disgusting from having tortured them and then fed them afterwards.
You shouldn't hurt animals and then feed them to get them to like you. That's not right, you can get them to like you in other ways.
They'll be fine. Don't worry about it.
It really sounds like you are playing with the emotions of this animal. Animals deserve to be treated right as well!