Taking care of a furbutt is like raising a child that will never grow up.
No parents is perfect and we all try our best to give them the best possible life we can offer! Please don't feel bad or guilty. If you look on the bright side, you're preventing one more hazard that might have actually really done him a lot of harm.
Gizmo is a fighter just like his mama so I'm sure he'll be back to himself in no time!
ps. How about some chicken broth with the rice/chicken breast? The smell from the broth usually does the trick for my two when they don't want to eat.