Iphone 12 shutting down after being unlocked

My iPhone 12 froze on me, so I went to do a force reset, but before I could slide, it went to a black loading screen for a while. During this time, it would pop up with my lock screen and then immediately go back to the loading screen. After a while, the iPhone will go to and black screen with the apple logo. It would be like this for a while, and then my lock screen would pop back up. At this point, I picked up my phone and was able to put in my password to unlock it but immediately after, the whole process repeated. What is causing this? How do I fix it?