Can stress cause depression? If so, how to deal with it?

I've been extremely over-whelmed with school, volleyball, clubs I am in, social life drama, family problems, and so much more. I have no social life because I'm either at a volleyball game until 9:00pm, doing homework until midnight, or I'm rigorously studying for my AP classes. I don't get to see my own nephew and family, I don't get enough sleep, and I'm feeling like the person I am is changing. I naturally strive to over-achieve, but lately I don't even wanna try and I don't see the purpose of it anymore. I know I'm not a sad or depressive person, but lately I feel like... I can't believe I'm saying this... But I feel like dying. I have a really rough family life, a lot of verbal abuse and cruelness. I don't see the purpose of life when people are so disgusting, deceiving, and uncaring now a days.. Please, I need help from sincere people. If there is any.