Otherwise you may be out of luck. Still it seems strange that everything would just be gone... When you say everything is gone, do you mean that the server comes back up and it all works but just has no user data? If so double check that you aren't accidentally launching into the live environment ie if the TKL CD (or ISO if its a VM) is in the drive that it's not just booting off that. The other possibility is that you were already running off the live CD? But surely you would've realised that before if this server has been running for well over a year...
Did you have TKLBAM confgured?
If so then you can restore a backup using that.
Otherwise you may be out of luck. Still it seems strange that everything would just be gone... When you say everything is gone, do you mean that the server comes back up and it all works but just has no user data? If so double check that you aren't accidentally launching into the live environment ie if the TKL CD (or ISO if its a VM) is in the drive that it's not just booting off that. The other possibility is that you were already running off the live CD? But surely you would've realised that before if this server has been running for well over a year...