I'm tired

How do we deal with stress? I'm under quite a lot of pressure right now. My life is chaotic with work and school. I have a professor that LOVES to give out homework, he loves it so much that I have daily quizzes and weekly assignments. And work is endless, besides basic care of 80 animals I have 2 different genetics experiments(that's with no experience in genetics at all) and some behavioral stuff that I have been trying to start for the past 2 months. Then I get home and the dishes are not washed, cats need to be fed, clothes washed, bathrooms cleaned, medicine picked up, bills paid, and food made. Plus my great grandmother is dying and there's family coming in from all over....And my parents have essentially given up on my little brother and I am having to help him out of his teens and into adulthood while paying all his bills. I am very tired these days.