iPod not syncing to my new computer

Alright, so I recently got a new computer, and had a ton of trouble transporting my iTunes library over to my new computer from the old one. I ended up trying to use my iPod Nano as an external hard drive as the Apple support how-to instructed me. It ended up erasing my entire library from my iPod and it didn't work anyways because I hadn't enough room to fit my iTunes folder onto it.

So my iPod has been empty for a week and a half, and I've been trying to get it to sync to my new computer to put all my songs back onto it, with no luck. I think it's because it recognizes my iPod still as a hard drive, and not an actual music player.

My question is: How do I reverse this process so I can put my songs back on my iPod?

Please help. This has been a pain in the butt for two weeks, and it's really got me aggrivated.