I don't blame you! I upgraded to iTunes11 only because it will be necessary eventually, given Apple's policy of dropping older versions. All I can say is that I really miss Steve Jobs. He had a design sense of how to make things accessible, which is what made them popular. Between the Maps fiasco on the iPhone (I wish they would just give me Google Maps back and keep customers above their petty disagreement with Google) and this new user interface for iTunes, his successors are proving they lack his visionary ability.
With iTunes 11, I miss the ability to have everything on one screen so I can simply drag songs where I want them, and see all the songs along with all the playlists and what's on my iPhone or iPod all at once. With everything visible, it made it a breeze. Why would I want to have to go through drop down menus and layers, which take extra steps and time? This supposedly new feature of seeing a window with only the album or playlist actively playing was always available with a mere double-click. That way, it was an option - one I rarely chose. I surely don't want it as the default -- and I surely don't want layers of drop-down menus to perform tasks I used to do all on one screen with ease.
While I've been figuring out how to drag and move songs around, and it all seems to work, it is less visible, less intuitive, more complicated, more time consuming. Without Jobs, the new Apple team is going to turn their company into a Sour Apple. I hope you guys read this forum and will consider putting your tail between your legs, admitting that you made another mistake, and return to the old user interface for iTunes.