Im really really sorry to hear that- youre free to grieve and if your home isint a safe space to do that I would recommed finding another outlet- try doing the bare minimum at school in order to keep your mind free and unoccupied so you can have some room to think. The weekend is coming up as well so maybe try to greive openly through that time- maybe even try to get some closure. Make a small grave for your cat in the backyard, even if its just putting some flowers outside, as that helps.