iPhone 4S can't sync music from iTunes...many fixes tried

In all my years with iPhone and iTunes I've never had a single issue, so I must be really doinking something up here. First, yes I have searched here endlessly and tried all the fix suggestions I can find but haven't had any luck. Oh yeah, my details: 4S obviously, upgraded to ios 7.1 (or whatever this latest is), running the latest and greatest iTunes version, doing all of this on a PC.

My issue: I can't get any music from iTunes to my 4S. When I sync, nothing moves over. When I'm on the "Music" tab for my phone-sync, no matter what playlist I select to sync, it says "0 songs" to be moved over. It is like all of my playlists are empty. If I leave the phone area and just look at my itunes library, all of my playlists are there and have songs in them, all of the songs play just fine. If I drag the playlist from the left to the right side of the screen and drop it on my phone, nothing happens.

What I've tried:

1. I first tried unchecking the "sync music" box and syncing my phone as others have suggested. I think rechecked the box and nothing changed. The fact that as I checked the playlists to load the top still said "0 songs" indicated it wouldn't work, then it didn't.
2. I made a backup of the phone and then restored as new. I did a full restore, chose to setup as a new phone, and tried to sync a playlist. It worked perfectly. Both playlists I drug over and dropped on my phone synced and played on the phone. So I then reloaded the backup, and playlists won't go on the phone again. So this tells me it must not be an iTunes or a phone issue but something with my profile/whatever (not a techy guy).
   

As far as I can tell, everything else on this phone works perfectly. This all started about two weeks ago and I've just been dealing with it, but really started to tinker last night.

Hoping someone here has another idea to try. This is a 4S and my applecare ran out late last year (november I think), so I'm due for a new phone anyways but hoping to limp this one along until the new iPhone comes out this year. Not the end of the world if I don't get music back, but if its starting down a path of corruption then I fear what might crater next.

Forgot to add, I don't have iTunes match turned on. I've seen a few people suggest that is an issue, don't think it is mine.