Oh man, it's just the worst when things like this happen. Unfortunately, you would have needed to back up the messages using an app, and stored the pictures on a cloud service or SD card. If they were only on the phone's memory, we won't be able to get them back. Sorry my friend.
It seems that you still have a chance to recover the messages and photos, but you need stop adding new data to your phone and the root is need for your Samsung in order to recover data from phone memory.
I know what you mean , stop using Samsung , in order to prevent data from being overwritten on Samsung ,
But there's one thing that you might miss ,the time also affects data recovery
Actually, if the deleted text and pictures on Samsung Galaxy S4 are not overwritten, it's easy to get them back with the help of pro phone data recovery tool. Of course, if there is a backup, you can easily recover from backup file.
In fact, maybe you just need a Samsung Data Recovery to Recover your Deleted Pictures and Text. But before starting to recover the photos there is something you need to know: you are not supposed to use your Samsung phone once your photos are deleted, because any operations may make your data overwritten so that your pictures can never be recovered, so does the text.
If you have synced your photos to the Google Photos app for backup previously, you can recover deleted photos from Samsung via Google backup. Here is how to do:
Open the Google Photos app on your phone.
Tap “Trash” from the top-left menu, all the deleted photos will be listed in details.
Touch and hold the photos you’d like to recover, then tap “Restore” to get the deleted photos back from Samsung phone.
If you haven't backup photos to Google account or Samsung account, you can use a thrid-party Samsung data recovery to recover deleted photos from Samsung.
What's more, the Samsung recovery tool also can help you recover deleted SMS on Samsung Galaxy phone, including Galaxy S10/S9/S8/S7/S6/S5/S4,etc.