Transfering music
So I havent transfered music in a while and Tonight I'm trying to transfer a new CD I just got and it's telling me that I can't because my phone is linked to another itunes library but I'm using the same computer I always use because it is the only one I own. I dont want to erase and start over because I dont have all of the music that was on my computer anymore. What am I doing wrong? Is there a way to fix it?
iPhone 5, iOS 7.0.4