I think that might be the best thing to try right now. First, make a note of how your current homescreens are set up, so that you can set them up easily again. It sounds like the launcher app is called "Home," so look for it in the Settings>Apps>All menu, tap it, then start by tapping Clear Cache (which won't erase your homescreens). Go back and try the App Drawer again. If that doesn't work, then go back to Settings>Apps>All and this time select Clear Data, and Force Stop. Now tap the Home button again, and you should see your homescreen show up, this time blank. Now see what happens when you tap the App Drawer.