Unable to Save, Unable to Load

[Pandapop v2]

Three days ago I've begun to lose my save files, and I've been unable to load some of the already existing ones. Just 20 minutes ago, I was on my newest toon -- reached level 8, had some ♥♥♥♥ done, all was going well... until suddenly, as I go to save, all previous saves began disappearing... and no new saves were added in their place. AutoSaves? Forget about it.

Yes, I HAVE backed up my save files, and yes, I have searched for them in their proper folder. What I see there are the last few saves of my very first toon... and one autosave from who-knows-what. Probably that same toon.

None of my newer stuff was in there. I searched high and low and still cannot find those saves. Needless to say, I think they're gone for good.

I had to get out of Skyrim and lost my newest toon, because I couldn't ♥♥♥♥♥♥♥ save. Couldn't use F5, couldn't manually save, couldn't get the game to auto-save by fast-travel or entering/leaving a building.

I have two of the DLC's downloaded - Hearthfire and Dawnguard. Had Dragonborn too, but for some reason, ♥♥♥♥♥♥♥ Steam claims I never bought it. Uh what? Thanks for eating up that $20, Steam.

I do also have some mods installed, but these mods I've had for a while, and never seemed to cause any problems before in the past. So I'm having a hard time believing they're the cause of the 'unable to save' issue I'm having.

What the hell is going on?