The data may be recoverable! If a quick format was done by your husband, then only the partition table was overwritten (the area that stores the volume formatting and physical locations of the files on the hard disk). Don't use the hard drive! Take it to a skilled recovery professional who can use special hardware to access the raw data in a "read-only" manner. They may be able to recover most, if not all, of your pictures!

Next time back it up

Always have backup.

never trust data to one place, or even 2.

I feel bad for you as I know what kind of stress you must have been under (my mother is a wedding photographer) but you're kind of an idiot for only having your pictures in a single place. Always have important files backed up.

Try formating again. On Harfdrives it sometimes works. Or google how to recover data from a harddrive.