Macbook Pro wont boot

I turned off my MBP 06 intel the other day and it wont start up again. It gets stuck at the apple logo and perpetual progress wheel however never gets any further. The battery is fully charged. I tried to enter safe mode however the grey progress bar loads about 1/5 of the way then stops and the progress wheel just keeps spinning until the battery dies. I have entered verbose mode and it says
**the macontosh HD could not be verified completely**
disk0s2 I/0 error .
Invalid key length (4, 16198)
invalid node structure
/dev/rdisk0s2 hfs exited with signal 8.

then a series of different things being disabled and the CPU shuts down. back to square one.

Any suggustions would be highly appreciated, Im really stuck, and I only purchased the laptop second hand 2 months ago.

Thanks.

Your hard drive has gone south.... you need a new one. Have you been making backups?

i survived that horror three days ago. have you tried running disk utility pressing the option key when the chime sound! then verify disk, then repair disk and disk permissions?