There are plenty of recovery software on the web that might be able to get some data off the card. After that you can try to format in a PC and then again in your BB and it might work after. I have done this on my 32 gig 3 times. Some times a file system gets corrupt. A good backup plan is a smart thing too.
Also the use of dropbox or similar service can be helpful, I use i as an auto backup for my device.
__________________ irony : many old timer posters have de-evolved into the trolls they once fought I am on http://supportforums.blackberry.com BES 10 running sweet for my Z10 and Q10
In This situation the only option you had left with is first format your memory card and use any reliable recovery software. you can find them on internet just serach for photo recovery software. May be you"ll get you data back with you.