How many straws is too many to eat?

I have a hard time setting boundaries in friendships and relationships so my therapsit said I should give everyone a certain amount of strikes. However, I need to physically visualize this so i decided to purchase straws (based on the saying "this is the last straw" lol) so I could visualize this. So everytime someone upsets me, I eat one of their straws to represent that straw being missing. Each month i buy three new straws for that person. Im a little worried that i shouldnt be injesting that much plastic, but i bite it into small peices and I havent had any problems yet. Should I be worried?