Recuva is another option as well. Software-based recovery tools are pretty much your only hope unless your budget for recovering this data is over $1000.
If this is your OS drive and the data is important, I'd recommend getting a new OS drive, installing recovery software on that drive and only then trying to recover from your hard drive. You want to avoid doing any writing at all whatsoever to the driver you're trying to recover, every minute you use that as an OS drive or installing software, you reduce the chances that you'll recover anything.
Hopefully you'll have a happy ending, but either way, I hope you take this as an opportunity to establish a proper course of backups. The only way to guarantee you don't lose important data is to make sure you don't lose it in the first place. There's a rule of thumb called the 321 rule meaning that at a minimum, you want three copies of your data, on at least two different forms of storage, and at least one located offsite. It's a basic part of PC ownership, no different than changing the filter on your furnace or the oil in your car and neglect can cause just as much damage.