Recovering pictures from Internal storgae
Android Data Recovery can recover your deleted/formatted files from Android devices without taking out the SD card or CF card inside the Android phone or tablet. This program has a strong ability that not only can recover photos and videos, but also can recover contacts, text messages, and other data. You can download it from the play store. 
I'm not sure if you've used backup photo apps but generally speaking Google photos automatically backup your photos. Try sending a text message and adding a photo as an attachment  it'll bring up a menu and it might show the places that your photos are saved to, you can also try downloading a file manager like ES and look for them there. Hope this helps.