Camera and Flash not working

Hello, yesterday 4/27, my phone camera and camera light is not working. I followed online tutorial how to fix issue by restarting my phone, updating IOS, change camera settings, and including shutting my cell phone that left it off by 5 min. Camera app still black screen on the app as well app does not take no pictures at all with button, and flash light is not turning on. One note I can also say, before using my phone yesterday morning, it seems it rebooted or something that it had white screen and black apple logo before letting me using my phone. Usually its black screen and white apple logo but not sure why that happen. Is their any guidance you can give me to help fix my camera?