It depends. Please contact your system administrator for help.
Users files are backed up every night. Chances are good that your files can be restored. Contact your system administrator for assistance.
A short answer is NO, do not even think about it.
Never reboot Linux computers without system administrator's permission. If you ever wondered, here is why: Linux is multi-user and multi-tasking operating system. Even if you are experiencing difficulties which you (unwisely) are trying to resolve by rebooting the computer, other users might work while logged remotely and/or several number-crunching jobs might be running in the background.
If you rebooted a computer by accident(?) contact the system administrator immediately.