4 days? wow - I must say, you are handling this better then I would be...
If you have backups - find another host and get your site back up !!
If you dont have backups - try every means possible to reach your host or their provider (Data Center) and try to get your server online long enough to grab your data.
You mentioned concern over the Sasser Virus - are you hosting on a windows server? Also - the fix for the virus is well known, worse case would be some (by some I mean what - help me out here any Windows Admins - 30 mins to install patch and reboot? )