Sometime yesterday, and I'm unsure of what could be the cause, all my media disappeared from my iPhone SE, running iOS 9.3.2 (64GB). There is nothing in my Music app on the phone except for downloadable songs I had purchased (but they're not local on my phone anymore), the movies I had transferred from the computer to the Videos app disappeared, all my podcast downloads had disappeared (they show up as saved, just the download for them is gone), my audiobook is gone from iBooks but other items there appear okay. Photos and Voice Memos apps also appear okay.
Checking in Settings, I don't appear to have recovered what should have been a couple GB of storage from the disappearance. And when viewing a breakdown of usage by app, it appears like Videos, Music, and Podcasts completely disappeared from the list, even though I did download about 5MB of data back to the Podcasts app.
I tried rebooting, no luck there. My first thought to fix this would be to connect to iTunes and have it sync and re-download all my content to the phone, but if that doesn't fix it or if I t leaves a couple ghost GB of data on my phone, that'll be concerning. And then I'm worried if I sync it, iTunes will back my phone up and then if I need to do a restore, I won't have a good backup to restore from (unless I can back up the backup and my iTunes library too?).
Anybody ever heard of this? What should I do?
Update: Tried poking around a little with iFunBox to see what's on the phone. Going to the raw file storage and then podcasts, there still are a few files that show up there, but not as many as there should be and not as many as show up on my iPad when I view the iPad through iFunBox. When going to the iTunes content and then Music, both on the iPad and on the iPHone, it shows a lot of folders with short file names, most of those have an MP3 when viewing in the iPad, but they all seem empty on the iPhone.
Is there a way I can back up my iTunes library and iPhone backup and then try a sync?