Whenever we get a hard drive for recovery, we advise to our customers to contact WD and let them know that data is important and that the drive would require opening up for recovery. WD honors that, as they understand that data is most likely more important than the drive itself.
Running your drive right now can actually be causing more and more damage to the platter if heads crashed, specially with the sounds that you describe. You see sometime heads can get caught up in parking ramp like in the picture bellow, and that can cause all kinds of nasty damage. So power off your drive and look for data recovery firm.