Hello, Sorry you're having problems. If your screen is lined at the top and white at the bottom, then it's almost certain that you need to replace the screen since ANY impact at all can cause the screen to fail. Since you dropped it and then this popped up, then that is the most common and likely issue here.
However, the problem you're having could ALSO be due to the software in the Kindle locking up and it needing to be rebooted. To do this, simply press and hold the power button on the Kindle for 40 FULL seconds, then release and wait a full minute for it to reboot (do no press anything else within that minute). If this does not cure the issue, try that reset up to THREE TIMES and wait the full minute to see if it reboots.
Please view my reply and try those steps so we can proceed.