Hi! Don't format it, if you still want to get back your information.
And then, you need to try a drive recovery freeware
that has helped a web friend restore his data back from a memory card. It can works well on a drive and memory card. So, if you are interested, you can visit it: http://blog4mark.blogspot.com/2013/01/memory-card-recovery.html
Oh! One more think, you should remember to back up your important information regularly in the future.