I sort of feel about that I've thrown away so much of my grandmother's food
Wow! Why are you wasting food like that?
I don't like to eat things that she made, and she ends up making so much of it and sometimes I don't touch them for weeks
You should be more considerate of your grandmother's cooking, you are very wasteful and ungrateful. She spends hard work and time on your food only for you to be a brat and throw it away. Show some more consideration and eat it.
My plan was to make her frustrated by wasting her food and get her to stop making so much.
Why don't you just tell her you don't like the food. Maybe she has some other recipes that you would like. At least she can stop wasting her energy and money making food for nothing.