Try booting it by holding the Home button and he power button simultaneously until the Apple logo appears on the screen, then you can let go the buttons. Wait until the iPod shows you the desktop. See if it is back working on panoramic view.
(Note: when holding those two buttons, you have to be precise and firm, or the iPod may just take a screen picture. Also, while you are holding those two buttons, first the iPod will turn the screen off then, after a couple seconds, the logo will appear---that's when you no longer need to hold the buttons)