Please don’t post “PLEASE HELP”, that’s not really a useful topic title.
https://codex.www.ads-software.com/Forum_Welcome#Choose_A_Good_Topic_Title
Your site has crashed. Do you or your host have a good file backups?
The first thing to try is getting your site up.
Using FTP or whatever filemanagement tools your host has provided you with and rename .htaccess
to .htaccess-old
and try your site again.
If that doesn’t work then download to your PC or Mac a fresh copy of WordPress 3.5.1.
https://www.ads-software.com/wordpress-3.5.1.zip
Then once again using FTP or whatever filemanagement tools your host has provided you with upload all the files and directories in that zip file except the wp-content
directory.
Hopefully that will fix it. Once that’s done and your site is working you can see if anything else has been compromised.