Well, do you think they could understand your depression?
Also, i don't know how old are you (don't need an answer, just trying to understand better in order to be helpfull), and please, don't get the question wrong but...
Can't you get a better job?
I could infer you aren't studying.
Also, the fact that your sister did something doesn't mean you can't do it, it's all in you my friend.