Message App Blank

Update:

So after hours on the phone with Apple Support and an appointment with a technician at an Apple Store, I finally resolved this issue. It was an incredibly frustrating process, so I figured I'd post the solution here in case anyone else encounters this issue.

The solution was to back up the iPhone to the iCloud, erase it of all data and settings, and set up as a new phone – not restoring from any backup. Whatever the source of the problem was, it was saved in the backups, and restoring with a backup would break messages again. By signing in on this new OS with your apple id, the essentials that you backed up to iCloud – your contacts, photos, notes, etc. – will be preserved and carry down onto the phone. However, the majority of your data, including all of your messages, will be gone. Sadly, this was the necessary cost of this solution, which as far as I could tell was the only way to fix my particular iteration of messages breaking.