Help! Instead of clicking on 'Restore the Backup', I clicked on 'Set up As a New iPod'

I used to have an iPod touch so i have a backup of that device on my computer. However, I lost the old one and now i have a new iPod touch. When i went to add the apps to the new one, instead of clicking on 'Restore the Backup', I clicked on 'Set up As a New iPod'. Now iTunes doesn't recognise the iPod and i cannot put apps, music or anything onto it! How can i go back? please help! Thank you