You may well have to wait until it loses power and shuts down on its own. Then let it charge while it is still off. Once charged start it up in "Safe Mode" and make sure nothing you have on it is the cause of the problem. Bad app, virus, malware, etc. Once you are sure things are good, then restart the device to get out of "Safe Mode". Note: You have limited access in "Safe Mode" so everything won't run. It is meant to stop problem items from running so you can remove them.
To get into "Safe Mode" please do the following.
1. First turn off the tablet.
2. Next press and hold "Power" until you see the manufacturers logo on the screen, then release the power button.
3. "Quickly" press "Volume Down" and hold it for few seconds until you see the message "Safe mode: ON" or something similar.
4. If you wanted disable it, simply repeat the steps above, and you should see "Safe Mode: OFF" rather than on.