I just opened up bitcomet and it said that all my downloads were 0% downloaded and when I check the ‘file’ thing, there is no files there to download and therefore I cannot start it again.
when I search for torrents and press the download button there’s a popup window saying ‘torrent task exited’ and just shows the downloading box without any files.
What’s wrong?! 
(I hope you understood how I meant. I’m tired and english isn’t my first language.. 
)
This sounds like you’ve had your settings disrupted, changing your default download directory among other things. First thing to try is a reboot, to see if that makes things return to normal. If that doesn’t solve it, check the preferences for your default download and default torrent directories. Also check the directories themselves to make sure they exist, and what they contain. You should see your incomplete downloads and your current torrents there.