Windows left nothing after clicking end process

Hello, and thanks for taking time to read this. It's a very loooooong story.

It happened after my antivirus freezes. After that, the end process message showed up. However I couldn't do anything to that message. Then I decided to shut down Windows, but it won't. Then, the antivirus reresponded. After that, Another end process message showed up. I didn't even know what to do, I clicked end process. The icons and taskbar suddenly disappeared and left my wallpaper and cursor. Few minutes later, the screen turned black and left my cursor. Another minutes later, the screen left comepletely nothing and it's black. My CPU is still flashing and seems to be powering on.

What should I do??? Pls help