How to recover NTFS volumes after accidentally formatting drive as JHFS+ volume?
I started writing up a long complex answer on how to recover your data using tools like Disk Utility to create a backup image and testdisk to recover the partition table, because that might be all you need to do.

But if you don't already have experience doing work like this and this data is valuable to you, you should really go to a data recovery specialist. At the moment this might be a simple fix, but a wrong step could make this much more complex.

Please find a local data recovery specialist and ask them to recover your data.