you say that you cannot access your old HDD,have you tried to slave it to another PC?
This may help, click here't-Have-the-Old-One
or this,click here
I am not sure if these will transfer your apps, it might be necessary to take a note of them and download them again. You will not have to pay for them again.
If you can access your old HDD then just copy and paste everything in the old itunes folder to the new itunes folder.