Major Macbook Problems! Everything Has Gone Missing!

I opened the mail application today, which I had my gmail account set up on. Upon opening the app, it wanted to guide me through setting up my account. . as if I had never set one up to begin with!!

And the REAL kicker - my iTunes library is GONE! Nowhere to be found!!!!!!!!!!!!!

It's starting to look more and more like just about EVERYTHING is missing from my system all of a sudden. All of my applications are still there. . but everything else is FUBAR. All my photos are gone from iPhoto and Lightroom. All my music is gone from iTunes. All of my passwords disappeared from my keychain.

I'm not happy. Can anyone help?!?!?!?!

You renamed your Home folder, didn't you?

Don't do that. The link you want is in the sig below.

Nothing to do with hardware, moving to software forum

Yep sounds like you manually changed the name of your home account. Never do that. There are correct procedures to follow on how this can be done and you'll find them in technologist's link he has in his sig.