Iphone white screen of death

My power button doesn't work i have to use the accessibility button in order to shut my phone off. So how can i fix this? A lot of videos show holding the power button and home button down but i can't hold my power button down, please help!

Old school technique:
You can squeeze (pinch) the Power Button top corner front glass to the back case while pushing the Power Button and the Power Button will usually function.
With the screen of death your options are way limited.
Best luck.