Aww... I feel for you, guy...
As soon as possible: Disconnect the drive until you've decided how to proceed. Fair Warning: anything you do from now on will likely make it harder for you to recover your data, including rebooting, not rebooting, or examining the drive using any number of built-in or additional tools.
The answer may be "Yes, you may be able to get back your data", but there are a LOT of variables and things that can go wrong here: quick vs. full, NTFS vs. FAT, and even IDE (PATA) vs SATA vs SCSI.
1st question: did you "quick format" or "full format" the lost drive? If "full format", the chances to recover your data are slim and expensive. Minimally, you'll need commercial software, probably you'll need another drive, preferably the same size, manufacturer and model (on which to make an identical copy of the lost drive), and you may need to send the drive and drive controller away to a specialized firm to recover the data.
If you "quick formatted" the lost drive, you may still need commercial software, but the time and cost to recover are less.
Quick formatting a drive erases the indexes or "table of contents" of the disk, while leaving the data on the drive, in place. The complexity is that most drives are heavily fragmented, meaning small pieces of your file may be stored all over your drive, rather than stored neatly in consecutive and adjacent sectors of the drive. Most OSes, like Windows, store a number of copies of this index, and sometimes one or more of these survives the quick format.
Drive interface type shouldn't matter, and doesn't usually, but some older, slower drives detected a full format attempt and substituted a quick format in order to save time.
I know you don't want to hear this now, maybe not ever, but this is why backups are so important...