Hey there, LX19.
It really sounds like the drive is done for. You should always have a backup of your most important data, or if you don't have one, at least make a backup as soon as you think that there might be something wrong with the HDD. It's a really unfortunate situation and I'm sorry you had to learn this the hard way.
If the reading head was the problem and if it got stuck on numerous occasions it is probably damaged a lot by now if the drive doesn't even start. However there is some hope at the end of the tunnel - you could go for a data recovery company to see if professionals will be able to recover your files.
Hope that helps.
Boogieman_WD