There is rarely, if ever, any sure-fire solution to a problem like this. I mean, you've already got so much stacked against you that there's nothing to do except to ride it out. Become better friends with your sister so that she won't rat you out in the future. Study hard and do well in school and get the fuck out of that house.
But I mean... seriously?
“It is a strange paradox that today’s central banks are generally staffed by economists, who by and large profess a belief in a theory which says that their jobs are, at the best, unnecessary, and more likely wealth-destroying. Needless to say, this is not a point widely discussed among respectable economists. Nevertheless, it is an issue worth pondering.”
George Cooper, The Origin of Economic Crises