Iphone 11 plus keeps restarting after I unlock my phone

My iPhone 11 plus keeps restarting after I unlock it. Only a few seconds after its unlocked it shuts off to the black screen with the loading icon. Then for about five minutes it just keeps showing the apple logo on and off. I plugged my phone into my mac and tried updating the software from it but it stopped after the update was downloaded. It is fully charged and I already tried the steps in the "If your iPhone turns on but gets stuck during start up" article, didn't work. I'm very frustrated at this point, nothing is working.