sorry to hear your problems, but its good your doing something about it, see what responses you get here.

As you say not a single kb has been written on it, then yes I believe its totally recoverable, a friend works in a data recovery studio for small businesses and he has shown me a few tricks that online recover programs dont do, an .img file is ok but I would need the exact make/model of the thumb drive, in worst case scenarios I will have to create a exact virtual partition of the size/block/segment of the drive you used, load it on and try a different rout.

good luck and I hope your future is more prosperous for you.