iPhone 11 keep restarting after I bought iCloud storage

At first my phone keeps restarting whenever I clicked on any apps and I tried to shut dow my phone but it just repeat the same thing, shutting down my phone then able to open then again until when I finally get to shut down my phone, the apple icon keep appearing but still not able to on my phone and still repeating now. Please reply as soon as possible, thanks! I saw one person have the same problem as me after he/she bought iCloud storage.