How did you do it in "error". Fdisk would have put up a dialogue box which said something like: "If you continue, this will delete everything off this disk". "Do you want to continue, Yes or No" Did you not read this?
This is why I always disconnected all but the disk where I wanted to use that awesome command.
With more than one HD particularly, it is very difficult to be absolutely sure which drive and which disk is which! (Some friend long ago formatted the wrong drive for me)... Some friend, but a lesson learned.
PC Inspector File Recovery. Arrowkey and Ontrack Easy Recovery can help recover deleted and fdisked data loss but at a cost but some of them may do a trial. BUT you must not do anything to the drive as the data will be over written anf totaly lost.