I'm writing a speech for school and a few times want to use the phrase, "piece of sh*t". Since it is for school I'd like to try a cleaner version of this just to be safe, but I still need something with a punch. I'm using that phrase for the harsher effect it gives and something like "piece of crap" just isn't doing it for me.
Any alternatives out there?
EDIT: some context. I'm discussing having negative thoughts about yourself confirmed by someone in amongst countless compliments. So if you're thinking to yourself "I'm a piece of sh*t", and one person says to you "you're a piece of sh*t", it sticks out in your mind no matter how many other positive things people say about you.