every application resets when macbook is restarted...HELP !

started to happen after downloading some torrents from the internet... Every time i turn my computer on, every program has magically reset itself, some times even the dock is differnt. my itunes is messed up, everytime it opens it gives me a damaged library... cant find imovie projects... any input is appreciated.

Do you have backups on an external drive? You can revert back to before the torrent download using Time Machine.