iMessage freezing, blank white screen

A few days ago my iMessage started acting weird. I get a message notification, usually on my Apple Watch, then try and open messages on my iPhone and iMessage opens to a blank white screen. When I swipe up to close the app the blank screen goes away and I can see my message history, but I can’t tap on any of the messages because it’s frozen. If I try to send a message it’s frozen. If I try to go to settings and turn iMessage off that setting is frozen. Powering down the phone and turning it back on makes everything work, but only briefly, before message is frozen again. What is going on?