How can I tranfer Itouch music to my Itunes library without them being overwritten?

[WhoDatSwag]

I just updated Itunes and my CPU and somehow lost all my music documents and music (mixtapes,albums,singles,etc.) Since all of the songs over the past 3 years are on my Itouch, I was wondering how can I transfer them to Itunes without having the "Itunes library writing over any existing songs" I have over 3000 songs on my Itouch and I dont want them to be erased for a blank library. Someone please please please please help me!

 

[mmmmmmmlvm¢mmmmme]

Plug your ipod into your laptop then when the usb thing pops up click transfer on your ipod, Then select the audio you wanna transfer