HELP WANTED: iTunes Guru

Here’s the situation: Feeling it was finally time to bite the bullet and check out iOS 7, I recently updated iTunes.

Yeah, I know. My first mistake.

When I started iTunes again, I saw that all of my media, playlists, etc. were gone. I wasn’t overly concerned about this, as I figured I just needed to click a box somewhere or something. But it wasn’t that simple. The instructions I found online told me how to find a previous iTunes library on my computer and use it to repopulate iTunes: http://support.apple.com/kb/TS196

But the most recent “previous library” I could find was from 2010. THREE YEARS OLD. (I don’t update iTunes all that frequently, but I’d certainly done so within the past three years.)

I found other instructions on how to re-create my iTunes library and playlists: http://support.apple.com/kb/TS1967

No dice. Even using the XML file, the most recent version I could find was 2010.

No problem, I figured—this is why I have a backup drive. I’ll just pull up the right file from there and use it. But nothing worked. Whatever file I located either yielded no media and playlists at all, or else the 2010 version.

I realize that all my media—songs, videos, apps, etc. are still there. It’s not that they’ve been deleted—iTunes has just lost its record of them. And because I chose the setting to allow iTunes to organize those files, they’re all together in my iTunes folders. That’s a plus.

Another plus is that most of the playlists I’ve built are still intact on my iPhone. It’s a pain copying them off one by one, but they’re still there. (Another issue, though, is that when they point to any tracks that I’ve added in the past three years, iTunes rejects those tracks from the list because it thinks they don’t exist. Oy.)
So here’s my question, iTunes gurus: What do I do next? If there’s a method I haven’t tried for recovering my old data, that would be the best solution. If not, what are my next steps? Do I start with a clean slate and have iTunes re-locate all my media? Do I start with the 2010 version and do the same? Will I need to copy all the playlists from my iPhone? In the (many) cases where I’ve pulled album covers off the web to accompany the tracks, am I going to have to make those connections again?

I’d appreciate any advice (other than the “iTunes sucks” or “use Linux” variety) you can give me.