IMac 2006 Hard drive not recognized

Hello, i own a 2006 imac with a 120gb hdd. Recently it's been working slow on me, as in a bunch of rainbow wheels when going on finder, etc.

I decided to boot up my install disk (10.6 Snow Leopard) and verify and repair the drive. Not surprisingly, when verifying an error came up. It said "invalid node structure" and literally 5 seconds after that came up, the entire mac froze. The cursor couldn't move or anything.

I waited 15 minutes to see if the imac would unfreeze before deciding to do a hard reset, so i unplugged all cables, waited another half hour, then started it up from the install disks again. Now, when i go into disk utility, the drive isn't even recognized!

Is there any way i can fix this without going to the apple store? This is the first time my HDD has been acting up in the 6 years i've owned this computer.