Applications :: ITunes Library - To Replace Existing Folders'

I copied my cousin's itunes music folder onto my external hard drive so I could add it to my own.

I dragged the artists into my iTunes music folder.

I was asked whether I wanted to replace existing folders... e.g we both had "Arctic Monkeys" folders.

I CLICKED REPACE ALL... What a mistake.

I'm very much into music and I have lots of songs, whereas my cousin only had a small library.

Now, my "Arctic Monkeys" folder only has a few songs in that she had, and i've lost loads from my library from many artists that both of us had.