how do i recover deleted text messages off my phone

If you have turned on iCloud Messages you can't recover them. If you have not, and they are in the last backup you did, you can do this -> Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

You will lose any data added to your iPhone after the date/time of that backup.

If you did not enable messages in the cloud, restore the phone from a backup made when the messages were still present.

If you did have messages in iCloud turned on, they are gone. You can't get them back.