It could be that your touchscreen isn't working. There was a large problem with Nexus 7 getting stuck, but it was a little different where it would only show the google logo. There's an interesting solution which helped a lot of the time, not always. Try it maybe it'll work for you as well.
Turn off your device. Press the power button and the low volume button together, which should startup service mode. Press the volume up button, select start. Press the power button. Now lightly tap the back side of your phone.
Please report back if that worked.