I would try the method posted above, with Recuvia, using the SD card reader, and not your phone. I found a download link via Filehippo.com which is a trusted source for downloading programs.
(I use it all the time)
Download Recuva 1.47.948 - FileHippo.com
I have never used this method, but found a youtube tutorial with a walkthough on helping you recover your files, that is here:
Tutorial: Recover Deleted Computer files with Recuva - YouTube
If you're the type that enjoys reading your tutorials, I found this tutorial:
How to Recover Deleted Files Using Recuva
I very much hope you're able to recover your missing files.
I have not heard of anyone messing up their SD card by rooting(it is likely your SD was close to failure already), and I've been around since close to the beginning of Root for the Fusion 2; I've also read just about all the posts related to this phone.
If you try this method for recovering your files, will you post back with the results?
Best of luck.
-Ze