Chances of getting my harddrive recovered
You are likely doomed.  The store gurus will go over data recovery options and explain they don't fix damaged drives, they are simply going to ask about the status of your backup and whether you want them to test the operation and see if it needs to be exchanged under warranty / AppleCare. 

Some things to try on dead and near dead drives include putting them on their end or sides rather than having them oriented flat - this is because the read/write heads that sit between the actual disc platters may respond better then they are held vertically by gravity rather than horizontally by their precision engineering which sounds like it;s been compromised.  Give it a go, see if it sounds any better (assuming you are not using an iMac where they are are already mounted this way).

Sorry to be the bearer of bad news.