You may have to perform a hard reset to restore your Kindle.
A Kindle touch can be fixed by resetting, though your credentials and data may be lost through the entire process.
The reset on this device is a hard reset
Make sure the Kindle is turned ON. This is an important step!
Press the Power button for at least 20 seconds. It should turn off at about 20 seconds.
Wait for it to reboot – wait a minute or two. If it doesn’t restart on its own, press the power button to turn it ON.
Your kindle should be back to a responsive state.
You will have to go through the setup again and then synchronize to put your e-books and other data back on the device.