I'm really sorry to hear about your sister, and I know how cancer can be. My friends dad passed away from Cancer a while back. Anyways, about your depression, it seems pretty obvious it was brought about by your sisters cancer issues. I think you really just need someone to talk to and someone to listen to you. A therapist can do wonders, and are really there to provide moral support and just to hear you out.

Another idea is to just confide in your closest friends. Depression can often be the cause of tons of built up and repressed emotions, which is common when having to deal with a lot of things at once (ie. school, work, parents, social life, with the added sister having cancer). Sometimes the best way to relieve all that depression and changing moods is to just let it all out to someone, they don't even have to talk, just so you can know someone is listening to how you're feeling.

Also, remember that even though your sister has all these problems, she is also alive, and she is mentally strong! She is staying tough so take pride in that!

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