PLEASE HELP!... I need to uncompress my pictures

We switched from Windows to Macs only a few months ago, and while we love all the things my Macbook Pro has to offer we don't really know how to work it good... Anyway, my problem is my husband compressed and exported all my pictures (thousands of them) from iPhoto to my external hardrive. The point was to free up space in my internal hardrive, and create a "referenced library" to access my pictures instead of having them in iPhoto. After all the pictures were transfered to the external hd and I tought they were safe I deleted the library from iPhoto and emptied my trash.

Now the problem is I can't seem to be able to create a reference library and to make matters worse when I imported some of the pictures back to iPhoto they are very small, like thumbnails... I'm freaking out because I don't know what to do to get my pictures back to normal to be able to edit and print them. Please help!