Answer:
Lovely and round I shine with pale light grown in the darkness a lady's delight.
You throw away my outside you cook my inside. Then you eat my outside and you throw away my inside.
I stink in living but when dead smells good.
What has to be broken before you can use it?
My keepers feed me colored balls. With sticks they store on my den walls. Sometimes I store them in my pouch. Sometimes deep in my belly; ouch!
No matter how little or how much you use me, you change me every month.