I'm so sorry to hear that. There are several utilities that may help you to recover the photos. One of the best, ***** ***** opinion is Recuva. It's definitely the best one to begin with. You can download it free of charge and test to see if it can recover your files before you pay for the full version. Please download and install Recuva from this link http://download.piriform.com/rcsetup153.exe and then follow these steps to see if it will be useful:
Insert the SD card into your computer. If prompted to format the SD card, check the box next to “Quick Format” and then click “Start”. This will erase the SD card’s table of contents and leave the data untouched.
Return to the Recuva program and click “Next” to proceed from the Welcome screen.
Select the type of file(s) you would like the program to recover then click “Next”.
Select your SD Card as the file location. Choose “In a specific location” and then click “Browse”. Scroll through the list and select “Removable Disk”. Select the “DCIM” folder if needed. Click “Ok” followed by “Next”.
Click “Start” to run the program. As the program recovers files, they will appear on the screen.
Check the box beneath each file you would like to recover.
Select a location to save the files and then click “Ok”. The files will be restored to the location you selected.
Click “Ok” once the restoration process is complete.
Navigate to the location you selected in step 14 to view your recovered files.