Recently I accidently deleted all of my messages on my Samsung S3 phone. I lost all my messages and noticed my photos in Galaxy app also disappeared. Does anyone know of a way to retrieve the deleted data.
Welcome to Android Central! SMS messages are stored in an SQLite database in a protected system directory -- it wouldn't be a file that was deleted, so you can't recover those.
Were the photos that disappeared associated with those messages, or were they photos you took with your camera? Use your My Files app to look directly in the directory where the photos should be (/DCIM/Camera, if they were taken by the Camera app) -- can you see the image files there?