Can't open phone


When I click the power button on my phone, it brings me to the usual opening screen showing various messages. When I swipe up I'm brought to the screen asking for my PIN. I enter it correctly, but instead of bringing me to the home screen it brings me back to the opening screen. If I swipe up again I'm brought to the PIN screen in an endless loop. The only app I can open is the camera, shown as a icon on the lower right of the opening screen. If I open it, then tap the "Home" button at the bottom of the screen, I'm once again brought back to the opening screen.

How can I open my phone?