I have a WD Caviar Green 1TB, bought it in the year 2010, recently I made an upgrade to my computer, at first the hard drive was not reading it freezes my boot screen. I tried other older machines it worked twice on older motherboards, the first time I was able to browse my local drivers via mini xp using Hiren Boot CD's the second was only on boot it was detected on the motherboard then died....nothing. I didn't even had the chance to backup my data, I tried the freezing method, left it for couple of hours in my freezer, plug it to my computer it does't freezes my boot screen, it reads just (0.0GB) on my boot no model not even the brand then still nothing it only clicked twice not constant, powered but not detected on windows.
It sounds like your only option is to send it to a professional. It isn't cheap but if your data is important it's the best option. I think trying to do any more yourself is only going to make your chance of retrieving your data smaller.