Play mode enters full screen/ cant exit?

When I go into play mode, everything else goes black except for the game window and the top toolbar that has file, edit, etc. I cant exit play mode with any key shortcuts I have to kill unity completely and reboot, but if i test my game it will happen again. Can somebody please help? This screenshot is after I pressed ctrl +shft + P and then clicked save. I can't even use the engine because of this.