Can't run on Mac after performing Wipe Free Space Only
Try to hold command-R on startup, open Disk Utility, and repair both the OS X volume (indented below the whole disk) and the whole disk. The Repair Disk button performs different actions depending on whether a whole disk or a volume is selected.

If you still cannot start up in OS X, you can try to reinstall OS X by starting up from the recovery partition and selecting Reinstall OS X. It installs a new copy of OS X over the current installation but keeps your files and settings in place.

If you don't already have backups, you can save a disk image of the OS X volume from Disk Utility. See http://support.apple.com/kb/ht1553.