iphone 6+ goes crazy after upgrading to iOS 11.1.1

I use iphone 6 plus. I upgrade iOS to 11.1.1 on 12/11/2017. My iphone has gone crazy afterward. The keyboard does not work or automatically types nonsense word. When I launch Google app, it automatically searches what I have searched before the update. However, the keyboard does not allow me to type. Search function is launching randomly as I open different app. When I try to play Candy Crush, the touch screen does not respond accurately in spatial aspect. The Control panel cannot launch by swiping upward. Sometimes, app launches randomly and automatically.