IPod will no longer sync with iTunes

Question

I started a thread before about how I could no longer sync the e-books I added to my iTunes account to my iPod touch. I'd found a workaround by e-mailing the books to myself and then opening them in iBooks on my iPod.
Now however I'm having the same issue with ALL THE CONTENT in my iTunes account. It still recognizes my device. I HAVE updated iTunes and my iOS (my iPod touch is 4th generation so I don't have/can't get iOS 7). I have uninstalled and reinstalled iTunes altogether. I have made sure the right boxes are clicked before syncing. It will go through the sync but the part where it says it is adding the files and shows them adding individually never happens. It just jumps to step 4 finishing and then when I check it never appears on my iPod. This is frustrating. What point is having an iPod if I can't USE it? It's basically a $200 paper weight. And YES I'm using the same apple ID, the same computer, etc. I've always used and I never had any problems before until a few months ago. It just stopped working. I've done most of the things suggested in all the other support threads I've read about similar issues and nothing has worked. Obviously lots of people are having this issue but from what I can tell the suggestions people are offering don't seem to help them.
So I guess I'm just putting this out there in the hopes that someone has a new idea to offer that will actually work? If not, does anybody wanna buy a 4th generation iPod touch?

Answer 1

I did restore from back-up as well. And I had thought of restoring my iPod to factory settings however...I just got my mother-in-law's old iPhone 3GS. Upon getting it from her I restored it to factory settings. After having the problems tonight syncing my iPod to iTunes I tried syncing the iPhone. It started out fine, showing it as a new device and setting it up. It shows both devices on my iTunes and then when I went to sync it I got the error message that none of the songs could be copied from my iTunes because they could not be found. But they all clearly show up in my iTunes. I had done this before when I was having the issue with my books and then I had deleted them all from iTunes and readded a few that I wanted to put on my iPod and it still wouldn't sync them. So I really don't want to take absolutely everything off my iPod and restore it to factory only to be unable to add anything from my iTunes ever again as is the case with the iPhone.