cant boot mac, have tried various things

Hi all, i would appreciate if anyone could give me some help. I try to give as much detail as to what happen so far below.

My Macbook pro 2009 5,3 recently started acting up. Initially i was able to login fine etc, however i was playing a video and it started to pause and freeze. My computer locked up and i had to restart, however once back into mac it would go very slow and applications would hang and i would need to leave them for a min to unfreeze. I noticed this happen shortly after upgrading to osx 10.8.5 from 10.8.2 (not sure if its related). Over time the startup became very slow and sometimes i could not get past the grey spinning cog with the apple logo. So:

I tried reseting p-ram, and doing a cmd+s single user mode and running the 'fsck -fy' etc which worked, i was able to log back into my mac but it was still very slow and apps locking and freezing and had to hard restart.

I also did a option+cmd+r to go into repair mode on startup, i ran disk utility and did repair permissions and disk repair (In the disk utility it seemes the hdd was fine and s.m.a.r.t was ok), that seemed fine but still it would take ages to login and even load an app and had to hard restart in the end.

Now i cant even login or access single user mode properly(explained below), i cant run recovery on startup spinning cog just locks or keeps going forever, i cant run the install cd while holding down C the spinning grey cog just stops after a long wait. I can run hardware dianostics while holding D with the applications dvd, i have done this and it says the ram is fine (not sure if this tests hdd) but i cant really do anything useful with it.

When i go into single user mode now it says some jiberish and then stops the text from coming down like it use to, then it waits a while, then says:

hfs_mountroot failed: 6

cannot mount root error = 19

disk0s2 media is not present

and keeps repeating this down the screen with some other jiberish.

It seems something inside has messed up even more and now disk0s2 cant even mount (probably why i cant access single user mode, recover mode etc..).

I had tried using some software called macdrive (hsf emulator kinda thing) and hsfexplorer on windows with a sata to usb adaptor (also sata to motherboard) but it did not connect properly and did not show up in my computer like it is supposed to. Does any one think that if i had not got to the stage where it cant mount disk0s2 problem it may have worked beforehand?

Do you think i could have backed up the drive with disk utility to a external HDD if i had done it when repair mode was working? (i am kicking myself if i could have)

Another thing i though was to go into single user mode and mount a external HDD and use the copy 'mv' command to copy the data over. When single user mode was working i could run the 'ls' command to browse directries and files where still intact etc, has anyone ever done this backup idea?

If possible if i can just get single user mode working again or repair mode working then i might be able to do some attempts at backing up. How can i get disk0s2 to mount like it should do?

How can i go about getting the data back from this drive? it is extremely important to me, some options i have thought of was to buy a duplicate drive and replace the platters (very hard) and see if that would work (might not even fix mounting issue). Right now i am freezing the drive in the freezer since some people say this works but i dought this will help, will try and boot it tommrow. Would it be possible for me to get a platter reading device that i can take the platters out and then put in a special device to read the data? Does any one know what the special white lab coat people use to do specialist recovery, i would be interested in buying that equitment.

I have read that some people have left the mac overnight with the spinning cog then the login might appear?

I am fairly sure all the files and data i need are still on there regardless of if the hdd is dead/dying/failing, its just the disk0s2 is not mounting properly so i cant access anything to try and recover and some osx system files might be messed up to.

Please help, much appreciated =)