What do I do when i broke my family apart?

ok, well one problem turned into another, which later on did the domino effect. now, my sister won't talk to my mom and dad, i don't talk to anybody, and I can't even go on yahoo without getting petrified about my sister confronting me on YM about all the shenanigans I made about how I should get permission from my 'rents about my choices etc. what do I do.