How do I get all of my songs from my I-pod touch 4th gen. to my I-tunes?

I was using a different computer before the one I'm using now for my i-tunes and i-pod touch, and that computer is where I first downloaded all of my songs. I can no longer use that computer because it broke. I-tunes works on this computer, I just cant get the songs from my I-pod onto my I-tunes. I've tried syncing like 400 times. and the songs all still work fine on my i-pod, that is just my only problem. I thought about restoring it, but I dont want to lose all my music and stuff. HELP! Thanks (: