You may have to wait for it to run out of power. Once it does. Leave it off and charge it a bit. Not a full charge, just a little. Then when you go to turn it on, turn it on in "Safe Mode" and make sure it loads up fine. Many apps won't work in that mode. So you will have to restart the tablet then.
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.