Hi, the first thing I will suggest you to do is not going to search method on Google to restore your photos, but stop using your iPod Touch to take any new photos, video, audio, also don't put any new photos, video, audio into your iPod Touch first.
You need to keep the suggestion above 'cause you still have a chance to retrieve your lost photos. But if you do the things above (means you put the new files into your iPod Touch), you may lose your chance to recover your photos. Actually it's not so complicate, I will explain it for you.
When you delete a file (no matter this file was deleted from iPod Touch, storage device like USB drive or other device, computer hard disk), this file is not really "gone" forever. The operating system only frees up the space which is taken by this "deleted file" so that the space can be used by the new file. Let me tell you like this: You delete "A file", the space of A file now is available for any other files. If this time you put a "B file" into the device which the "A file" was stored there before. The "B file" will take the space of "A file". Then you will lose the chance to recover your files. This situation is called data overwritten.
So you need to follow my suggestion to stop using your iPhone and start to find method or app to help in recovering your photos.
You can visit this post to learn more details about iPhone data loss and data recovery. Hope my answer can help you a lot: http://www.uflysoft.net/iphone-ipad-reco...