Q: sms messages are deleting themselves

Howdy Marie,

Welcome to Apple Support Communities.

It sounds like text messages are missing from your iPhone 5, and you aren’t able to recover them from an iCloud Backup. If you have a backup of your device in iTunes, you may be able to recover the texts from the iTunes backup as described in the article below:

Send messages with your iPhone, iPad, or iPod touch - Apple Support

How can I back up my messages?

iOS automatically saves your messages when you back up with iTunes or iCloud. If you ever lose your messages or switch to a new phone, your messages will be restored along with your other information.

This article will walk you through the process of restoring your device from an iTunes backup:

Restore your device from an iCloud or iTunes backup - Apple Support

iTunes

1. Connect your device to the computer that you stored your backup on.
2. Open iTunes. If iTunes tells you there's an iOS update, get the latest version.
3. Go to File > Devices > Restore from Backup. If you're using Windows and don’t see a File menu, press the Alt key.
4. Look at the date and size of each backup and pick the most relevant.
5. Click restore and wait for the process to finish. Your device will restart and then sync with your computer. Stay connected until the sync finishes.

Get help with this process, or read about encrypted backups.

Cheers,

-Jason